arm: atmel: at91sam9n12ek: add usb host support

Add usb host support for at91sam9n12ek board.

Signed-off-by: Bo Shen <voice.shen@atmel.com>
Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>
diff --git a/arch/arm/include/asm/arch-at91/at91_pmc.h b/arch/arm/include/asm/arch-at91/at91_pmc.h
index 003920c..7b36f74 100644
--- a/arch/arm/include/asm/arch-at91/at91_pmc.h
+++ b/arch/arm/include/asm/arch-at91/at91_pmc.h
@@ -233,6 +233,8 @@
 #endif
 #define		AT91_PMC_USBS_USB_PLLA		(0x0)		/* USB Clock Input is PLLA */
 #define		AT91_PMC_USBS_USB_UPLL		(0x1)		/* USB Clock Input is UPLL */
+#define		AT91_PMC_USBS_USB_PLLB		(0x1)		/* USB Clock Input is PLLB, AT91SAM9N12 only */
+#define		AT91_PMC_USB_DIV_2		(0x1 <<  8)	/* USB Clock divided by 2 */
 #define		AT91_PMC_USBDIV_8		(0x7 <<  8)	/* USB Clock divided by 8 */
 #define		AT91_PMC_USBDIV_10		(0x9 <<  8)	/* USB Clock divided by 10 */