km_arm: convert the km_arm boards to the generic board support

This implies that all the km_kirkwood boards and their variants now are
using the generic board init sequence.

Signed-off-by: Valentin Longchamp <valentin.longchamp@keymile.com>

include/configs/km/km_arm.h

@@ -20,6 +20,8 @@
 #ifndef _CONFIG_KM_ARM_H
 #define _CONFIG_KM_ARM_H
 
+#define CONFIG_SYS_GENERIC_BOARD
+
 /* We got removed from Linux mach-types.h */
 #define MACH_TYPE_KM_KIRKWOOD          2255