ARM: atmel: at91sam9n12ek: enable spl support

Enable SPL support for at91sam9n12ek boards, now it supports
boot up from NAND flash, serial flash.

Signed-off-by: Bo Shen <voice.shen@atmel.com>
diff --git a/arch/arm/mach-at91/spl_at91.c b/arch/arm/mach-at91/spl_at91.c
index e28e568..a79a9dc 100644
--- a/arch/arm/mach-at91/spl_at91.c
+++ b/arch/arm/mach-at91/spl_at91.c
@@ -115,7 +115,7 @@
 	timer_init();
 
 	/* enable clocks for all PIOs */
-#ifdef CONFIG_AT91SAM9X5
+#if defined(CONFIG_AT91SAM9X5) || defined(CONFIG_AT91SAM9N12)
 	at91_periph_clk_enable(ATMEL_ID_PIOAB);
 	at91_periph_clk_enable(ATMEL_ID_PIOCD);
 #else