ARM: rpi_b: enable GENERIC_BOARD

Serial port, SD card, and LCD all work.
Signed-off-by: NStephen Warren <swarren@wwwdotorg.org>
Acked-by: NSimon Glass <sjg@chromium.org>

include/configs/rpi_b.h

@@ -20,6 +20,7 @@
 #include <linux/sizes.h>
 
 /* Architecture, CPU, etc.*/
+#define CONFIG_SYS_GENERIC_BOARD
 #define CONFIG_ARM1176
 #define CONFIG_BCM2835
 #define CONFIG_ARCH_CPU_INIT