ARM: OMAP: Add CONFIG_OMAP_COMMON

Adding a new CONFIG_OMAP_COMMON which is included by all boards
that needs to build cpu/armv7/omap-common folder.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
diff --git a/include/configs/nokia_rx51.h b/include/configs/nokia_rx51.h
index 36c6800..cfc5f12 100644
--- a/include/configs/nokia_rx51.h
+++ b/include/configs/nokia_rx51.h
@@ -28,6 +28,7 @@
 #define CONFIG_OMAP3430			/* which is in a 3430 */
 #define CONFIG_OMAP3_RX51		/* working with RX51 */
 #define CONFIG_SYS_L2CACHE_OFF		/* pretend there is no L2 CACHE */
+#define CONFIG_OMAP_COMMON
 
 #define CONFIG_MACH_TYPE		MACH_TYPE_NOKIA_RX51