ARN: at91: introduce SOC_AT91xxx define to allow to compile SoC core support

We can now compile all SoC core support together and DT boards.
We still can not compile together the non DT board.
So We keep the ARCH_AT91xxx for the non DT board and for backward defconfig
compatibility. This will enable the plaform_device ressources.

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
diff --git a/arch/arm/configs/at91rm9200_defconfig b/arch/arm/configs/at91rm9200_defconfig
index bbe4e1a..d54e2ac 100644
--- a/arch/arm/configs/at91rm9200_defconfig
+++ b/arch/arm/configs/at91rm9200_defconfig
@@ -14,6 +14,7 @@
 # CONFIG_BLK_DEV_BSG is not set
 # CONFIG_IOSCHED_CFQ is not set
 CONFIG_ARCH_AT91=y
+CONFIG_ARCH_AT91RM9200=y
 CONFIG_MACH_ONEARM=y
 CONFIG_ARCH_AT91RM9200DK=y
 CONFIG_MACH_AT91RM9200EK=y