kirkwood: make MPP arrays static const

This saves stack and code memory for local copy, and
consumes initialized data memory. For 22 of the 29
kirkwood-based boards, this results in a global saving
of about 30 bytes. For 7 of them, it results in an
increase of 6 to 14 bytes.

Signed-off-by: Albert ARIBAUD <albert.u.boot@aribaud.net>
diff --git a/board/Marvell/guruplug/guruplug.c b/board/Marvell/guruplug/guruplug.c
index f5c1c3c..3a52ab2 100644
--- a/board/Marvell/guruplug/guruplug.c
+++ b/board/Marvell/guruplug/guruplug.c
@@ -43,7 +43,7 @@
 			GURUPLUG_OE_LOW, GURUPLUG_OE_HIGH);
 
 	/* Multi-Purpose Pins Functionality configuration */
-	u32 kwmpp_config[] = {
+	static const u32 kwmpp_config[] = {
 		MPP0_NF_IO2,
 		MPP1_NF_IO3,
 		MPP2_NF_IO4,