OMAP4: enable Thumb build

Signed-off-by: Aneesh V <aneesh@ti.com>

include/configs/omap4_common.h

@@ -287,4 +287,6 @@
 
 #define CONFIG_SYS_ENABLE_PADS_ALL
 
+#define CONFIG_SYS_THUMB_BUILD
+
 #endif /* __CONFIG_OMAP4_COMMON_H */