davinci: update DM644x support in preparation for more SoCs

Rework DM644x code into SoC specific and board specific parts.
This is also to generalize the structure a bit so it's easier to add
support for new SoCs in the DaVinci family.

Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
diff --git a/arch/arm/mach-davinci/Makefile b/arch/arm/mach-davinci/Makefile
index b27871a..1674661 100644
--- a/arch/arm/mach-davinci/Makefile
+++ b/arch/arm/mach-davinci/Makefile
@@ -9,5 +9,8 @@
 
 obj-$(CONFIG_DAVINCI_MUX)		+= mux.o
 
+# Chip specific
+obj-$(CONFIG_ARCH_DAVINCI_DM644x)       += dm644x.o
+
 # Board specific
-obj-$(CONFIG_MACH_DAVINCI_EVM)  += board-evm.o
+obj-$(CONFIG_MACH_DAVINCI_EVM)  	+= board-dm644x-evm.o