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/drivers/ata/mvsata_ide.c b/drivers/ata/mvsata_ide.c
index 9ac1655..6bbb345 100644
--- a/drivers/ata/mvsata_ide.c
+++ b/drivers/ata/mvsata_ide.c
@@ -10,7 +10,7 @@
 
 #if defined(CONFIG_ARCH_ORION5X)
 #include <asm/arch/orion5x.h>
-#elif defined(CONFIG_KIRKWOOD)
+#elif defined(CONFIG_ARCH_KIRKWOOD)
 #include <asm/arch/soc.h>
 #elif defined(CONFIG_ARCH_MVEBU)
 #include <linux/mbus.h>