arm: rmobile: lager: Enable CONFIG_SYS_GENERIC_BOARD

Add CONFIG_SYS_GENERIC_BOARD to use common/board_*.c for lager.

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
diff --git a/include/configs/lager.h b/include/configs/lager.h
index 7b47d2e..f39a788 100644
--- a/include/configs/lager.h
+++ b/include/configs/lager.h
@@ -42,6 +42,7 @@
 
 #define CONFIG_SYS_TEXT_BASE	0xE8080000
 #define CONFIG_SYS_THUMB_BUILD
+#define CONFIG_SYS_GENERIC_BOARD
 
 /* Support File sytems */
 #define CONFIG_DOS_PARTITION