arm: bcm281xx: Add CONFIG_SYS_GENERIC_BOARD

convert to generic board

Signed-off-by: Steve Rae <srae@broadcom.com>
diff --git a/include/configs/bcm28155_ap.h b/include/configs/bcm28155_ap.h
index e93b855..bf09939 100644
--- a/include/configs/bcm28155_ap.h
+++ b/include/configs/bcm28155_ap.h
@@ -14,6 +14,7 @@
 #define CONFIG_ARMV7
 #define CONFIG_KONA
 #define CONFIG_SKIP_LOWLEVEL_INIT
+#define CONFIG_SYS_GENERIC_BOARD
 
 /*
  * Memory configuration