[ARM] msm: rename ARCH_MSM7X00A to ARCH_MSM

The MSM architecture covers a wider family of chips than just the MSM7X00A.
Move to a more generic name, in perparation for supporting the specific
SoC variants as sub-architectures (ARCH_MSM7X01A, ARCH_MSM722X, etc).  This
gives us ARCH_MSM for the (many) common peripherals.

This also removes the unused/obsolete config item MSM7X00A_IDLE.

Signed-off-by: Brian Swetland <swetland@google.com>
diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index 7d51212..bd6e281 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -141,7 +141,7 @@
  machine-$(CONFIG_ARCH_MX3)	   := mx3
  machine-$(CONFIG_ARCH_ORION5X)	   := orion5x
     plat-$(CONFIG_PLAT_ORION)	   := orion
- machine-$(CONFIG_ARCH_MSM7X00A)   := msm
+ machine-$(CONFIG_ARCH_MSM)	   := msm
  machine-$(CONFIG_ARCH_LOKI)       := loki
  machine-$(CONFIG_ARCH_MV78XX0)    := mv78xx0