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/Makefile b/Makefile
index 1d67eaf..1cce381 100644
--- a/Makefile
+++ b/Makefile
@@ -2653,8 +2653,18 @@
 at91sam9260ek_nandflash_config \
 at91sam9260ek_dataflash_cs0_config \
 at91sam9260ek_dataflash_cs1_config \
-at91sam9260ek_config	:	unconfig
+at91sam9260ek_config \
+at91sam9g20ek_nandflash_config \
+at91sam9g20ek_dataflash_cs0_config \
+at91sam9g20ek_dataflash_cs1_config \
+at91sam9g20ek_config	:	unconfig
 	@mkdir -p $(obj)include
+	@if [ "$(findstring 9g20,$@)" ] ; then \
+		echo "#define CONFIG_AT91SAM9G20EK 1"	>>$(obj)include/config.h ; \
+		$(XECHO) "... 9G20 Variant" ; \
+	else \
+		echo "#define CONFIG_AT91SAM9260EK 1"	>>$(obj)include/config.h ; \
+	fi;
 	@if [ "$(findstring _nandflash,$@)" ] ; then \
 		echo "#define CONFIG_SYS_USE_NANDFLASH 1"	>>$(obj)include/config.h ; \
 		$(XECHO) "... with environment variable in NAND FLASH" ; \