at91: Support for the at91sam9g20 : Atmel 400Mhz ARM 926ej-s SOC.

AT91sam9g20 is an evolution of the at91sam9260 with a faster clock speed.

The AT91SAM9G20-EK board is an updated revision of the AT91SAM9260-EK board.
It is essentially the same, with a few minor differences.

Here is the chip page on Atmel website:
http://www.atmel.com/dyn/products/product_card.asp?part_id=4337

Signed-off-by: Justin Waters <justin.waters@timesys.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
diff --git a/cpu/arm926ejs/at91/usb.c b/cpu/arm926ejs/at91/usb.c
index a15ab16..7c44ad0 100644
--- a/cpu/arm926ejs/at91/usb.c
+++ b/cpu/arm926ejs/at91/usb.c
@@ -33,7 +33,7 @@
 {
 
 #if defined(CONFIG_AT91CAP9) || defined(CONFIG_AT91SAM9260) || \
-    defined(CONFIG_AT91SAM9263)
+    defined(CONFIG_AT91SAM9263) || defined(CONFIG_AT91SAM9G20)
 	/* Enable PLLB */
 	at91_sys_write(AT91_CKGR_PLLBR, CONFIG_SYS_AT91_PLLB);
 	while ((at91_sys_read(AT91_PMC_SR) & AT91_PMC_LOCKB) != AT91_PMC_LOCKB)
@@ -62,7 +62,7 @@
 #endif
 
 #if defined(CONFIG_AT91CAP9) || defined(CONFIG_AT91SAM9260) || \
-    defined(CONFIG_AT91SAM9263)
+    defined(CONFIG_AT91SAM9263) || defined(CONFIG_AT91SAM9G20)
 	/* Disable PLLB */
 	at91_sys_write(AT91_CKGR_PLLBR, 0);
 	while ((at91_sys_read(AT91_PMC_SR) & AT91_PMC_LOCKB) != 0)