adfuload: add test program

This test program. I add it mainly to document somehow my work:
1) atj213x.h    lists registers addresses
2) crt0.S       exploits self relocation of the binary
3) test_bl.c    documents how to control backlight on e150

Change-Id: I055e0fe065d926a5c3805b73cea3f537cb64bf52

utils/atj2137/adfuload/test_binary/backlight_c/test_bl.c

@@ -0,0 +1,42 @@
+#include "atj213x.h"
+
+static void backlight_set(int level)
+{
+    /* set duty cycle in 1/32 units */
+    PMU_CHG = ((PMU_CHG & ~PMU_CHG_PDOUT_MASK) | PMU_CHG_PDUT(level));
+}
+
+static void wdt_feed(void)
+{
+    RTC_WDCTL |= RTC_WDCTL_CLR;
+}
+
+int main(void)
+{
+    int i = 0, j = 0;
+
+    /* backlight clock enable, select backlight clock as 32kHz */
+    CMU_FMCLK = (CMU_FMCLK & ~(CMU_FMCLK_BCLK_MASK)) | CMU_FMCLK_BCKE | CMU_FMCLK_BCLK_32K;
+
+    /* baclight enable */
+    PMU_CTL |= PMU_CTL_BL_EN;
+
+    /* pwm output, phase high, some initial duty cycle set as 24/32 */
+    PMU_CHG = ((PMU_CHG & ~PMU_CHG_PDOUT_MASK)| PMU_CHG_PBLS_PWM | PMU_CHG_PPHS_HIGH | PMU_CHG_PDUT(24));
+
+    while(1)
+    {
+        /* otherwise wdt will trigger reset */
+        wdt_feed();
+
+        /* arbitrary delay */
+        if (++i > 30000)
+        {
+            i = 0;
+            j++;
+            backlight_set(j);
+        }
+    }
+
+    return 0;
+}