Nokia RX-51: Use generic board

Generic board with #define CONFIG_SYS_GENERIC_BOARD is working fine.
There is no visible difference between legacy and generic board code.
Signed-off-by: NPali Rohár <pali.rohar@gmail.com>
Acked-by: NPavel Machek <pavel@ucw.cz>

include/configs/nokia_rx51.h

@@ -28,6 +28,7 @@
 #define CONFIG_OMAP3_RX51		/* working with RX51 */
 #define CONFIG_SYS_L2CACHE_OFF		/* pretend there is no L2 CACHE */
 #define CONFIG_OMAP_COMMON
+#define CONFIG_SYS_GENERIC_BOARD
 
 #define CONFIG_MACH_TYPE		MACH_TYPE_NOKIA_RX51