arm: at91: add at91sam9n12 register definition

Since at91sam9n12 is a subset of at91sam9x5, so put all at91sam9n12
definitions in at91sam9x5 head file.

Signed-off-by: Josh Wu <josh.wu@atmel.com>
Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>
diff --git a/arch/arm/include/asm/arch-at91/hardware.h b/arch/arm/include/asm/arch-at91/hardware.h
index 4c4ee70..8812b11 100644
--- a/arch/arm/include/asm/arch-at91/hardware.h
+++ b/arch/arm/include/asm/arch-at91/hardware.h
@@ -37,7 +37,7 @@
 # include <asm/arch/at91sam9rl.h>
 #elif defined(CONFIG_AT91SAM9G45) || defined(CONFIG_AT91SAM9M10G45)
 # include <asm/arch/at91sam9g45.h>
-#elif defined(CONFIG_AT91SAM9X5)
+#elif defined(CONFIG_AT91SAM9N12) || defined(CONFIG_AT91SAM9X5)
 # include <asm/arch/at91sam9x5.h>
 #elif defined(CONFIG_AT91CAP9)
 # include <asm/arch/at91cap9.h>