ARM: imx: make all pin lists const and signed, move to .init where possible

Making the lists signed fixes sparse warnings like:

	arch/arm/mach-imx/mach-mx27_3ds.c:94:31: warning: incorrect type in argument 1 (different signedness)
	arch/arm/mach-imx/mach-mx27_3ds.c:94:31:    expected int const *pin_list
	arch/arm/mach-imx/mach-mx27_3ds.c:94:31:    got unsigned int static [toplevel] *<noident>

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
diff --git a/arch/arm/mach-imx/pcm970-baseboard.c b/arch/arm/mach-imx/pcm970-baseboard.c
index f490a40..7cffad8 100644
--- a/arch/arm/mach-imx/pcm970-baseboard.c
+++ b/arch/arm/mach-imx/pcm970-baseboard.c
@@ -31,7 +31,7 @@
 
 #include "devices.h"
 
-static int pcm970_pins[] = {
+static const int pcm970_pins[] __initconst = {
 	/* SDHC */
 	PB4_PF_SD2_D0,
 	PB5_PF_SD2_D1,