SPC Codec: Refactor for CPU and clean up some things.

CPU optimization gets its own files in which to fill-in optimizable
routines.

Some pointless #if 0's for profiling need removal. Those macros are
empty if not profiling.

Force some functions that are undesirable to be force-inlined by the
compiler to be not inlined.

Change-Id: Ia7b7e45380d7efb20c9b1a4d52e05db3ef6bbaab

lib/rbcodec/codecs/libspc/spc_cpu.c

@@ -113,9 +113,7 @@ enum { st_c = 0x01 };
 
 long CPU_run( THIS, long start_time )
 {
-#if 0
     ENTER_TIMER(cpu);
-#endif
     
     register long spc_time_ = start_time;
     
@@ -1036,9 +1034,7 @@ out_of_time:
     this->r.x  = (uint8_t) x;
     this->r.y  = (uint8_t) y;
  
-#if 0
     EXIT_TIMER(cpu);
-#endif
     return spc_time_;
 }