Add USB Audio 1.0 support

Original commit credit to Amaury Pouly, Moshe Piekarski
Pushed across the finish line by Dana Conrad

To enable, see setting under General Settings --> System --> USB-DAC.
On devices with few endpoints, this may not work while HID and/or
mass storage is enabled.

Adds new dedicated mixer channel.

setting usb-dac can have values:
- never (0)
- always (1)
- while_charge_only (2)
- while_mass_storage (3)

Relevant devices are DWC2 and ARC usb controller devices. That being:
x1000 Native targets (m3k, erosqnative, q1, others...?),
sansac200, creativezenxfi2, vibe500, ipodmini2g,
ipod4g, creativezenxfi, creativezenxfi3, sansaview, ipodcolor,
creativezenxfistyle, samsungypz5, sansafuzeplus, iriverh10_5gb,
tatungtpj1022, gigabeats, faketarget, samsungyh820, gogearhdd1630, samsungyh925, ipodmini1g, ipodvideo, creativezenmozaic, sonynwze370, creativezen, gogearsa9200, gogearhdd6330, sonynwze360, sansae200, mrobe100, iriverh10, creativezenv, ipodnano1g, samsungyh920

USB Driver-wise, it should be noted that this patch requires some
slight changes:
- proper blocking on control OUT transfers, to make sure the data is
  received *before* using it, the usb_core should probably use that too
- drivers can now support interface alternate settings
- drivers can be notified of completion by a new fast handler, which
  is called directly from the driver; this is is necessary for
  isochronous transfers because going through the usb queue is way too
  slow

Designware changes:

- enable for USBOTG_DESIGNWARE
- set maxpacketsize to 1023 for ISO endpoints

Change-Id: I570871884a4e4820b4312b203b07701f06ecacc6

firmware/target/arm/usb-drv-arc.c

@@ -599,11 +599,22 @@ int usb_drv_recv_nonblocking(int endpoint, void* ptr, int length)
     return prime_transfer(EP_NUM(endpoint), ptr, length, false, false);
 }
 
+int usb_drv_recv_blocking(int endpoint, void* ptr, int length)
+{
+    return prime_transfer(EP_NUM(endpoint), ptr, length, false, true);
+}
+
 int usb_drv_port_speed(void)
 {
     return (REG_PORTSC1 & 0x08000000) ? 1 : 0;
 }
 
+int usb_drv_get_frame_number(void)
+{
+    /* the lower 3 bits store the microframe (in HS mode), discard them */
+    return (REG_FRINDEX & USB_FRINDEX_MASKS) >> 3;
+}
+
 bool usb_drv_connected(void)
 {
     return (REG_PORTSC1 &
@@ -970,10 +981,8 @@ static void init_control_queue_heads(void)
 /* manual: 32.14.4.1 Queue Head Initialization */
 static void init_queue_heads(void)
 {
-    /* FIXME the packetsize for isochronous transfers is 1023 : 1024 but
-     * the current code only support one type of packet size so we restrict
-     * isochronous packet size for now also */
     int packetsize = (usb_drv_port_speed() ? 512 : 64);
+    int isopacketsize = (usb_drv_port_speed() ? 1024 : 1024);
     int i;
 
     /* TODO: this should take ep_allocation into account */
@@ -982,7 +991,7 @@ static void init_queue_heads(void)
         /* OUT */
         if(endpoints[i].type[DIR_OUT] == USB_ENDPOINT_XFER_ISOC)
             /* FIXME: we can adjust the number of packets per frame, currently use one */
-            qh_array[i*2].max_pkt_length = packetsize << QH_MAX_PKT_LEN_POS | QH_ZLT_SEL | 1 << QH_MULT_POS;
+            qh_array[i*2].max_pkt_length = isopacketsize << QH_MAX_PKT_LEN_POS | QH_ZLT_SEL | 1 << QH_MULT_POS;
         else
             qh_array[i*2].max_pkt_length = packetsize << QH_MAX_PKT_LEN_POS | QH_ZLT_SEL;
 
@@ -991,7 +1000,7 @@ static void init_queue_heads(void)
         /* IN */
         if(endpoints[i].type[DIR_IN] == USB_ENDPOINT_XFER_ISOC)
             /* FIXME: we can adjust the number of packets per frame, currently use one */
-            qh_array[i*2+1].max_pkt_length = packetsize << QH_MAX_PKT_LEN_POS | QH_ZLT_SEL | 1 << QH_MULT_POS;
+            qh_array[i*2+1].max_pkt_length = isopacketsize << QH_MAX_PKT_LEN_POS | QH_ZLT_SEL | 1 << QH_MULT_POS;
         else
             qh_array[i*2+1].max_pkt_length = packetsize << QH_MAX_PKT_LEN_POS | QH_ZLT_SEL;