rename symbol: CONFIG_KIRKWOOD -> CONFIG_ARCH_KIRKWOOD

Have this symbol follow the pattern of all other such symbols.
This patch also removes a TODO from the code.

Reviewed-by: Chris Packham <judge.packham@gmail.com>
Signed-off-by: Trevor Woerner <twoerner@gmail.com>
diff --git a/arch/arm/mach-mvebu/Makefile b/arch/arm/mach-mvebu/Makefile
index b739520..7e9c206 100644
--- a/arch/arm/mach-mvebu/Makefile
+++ b/arch/arm/mach-mvebu/Makefile
@@ -10,14 +10,14 @@
 
 else # CONFIG_ARM64
 
-ifdef CONFIG_KIRKWOOD
+ifdef CONFIG_ARCH_KIRKWOOD
 
 obj-y	= dram.o
 obj-y	+= gpio.o
 obj-y	+= mbus.o
 obj-y	+= timer.o
 
-else # CONFIG_KIRKWOOD
+else # CONFIG_ARCH_KIRKWOOD
 
 obj-y	= cpu.o
 obj-y	+= dram.o
@@ -73,5 +73,5 @@
 obj-$(CONFIG_ARMADA_38X) += serdes/a38x/
 obj-$(CONFIG_ARMADA_XP) += serdes/axp/
 
-endif # CONFIG_KIRKWOOD
+endif # CONFIG_ARCH_KIRKWOOD
 endif # CONFIG_ARM64