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/mach-mx21ads.c b/arch/arm/mach-imx/mach-mx21ads.c
index 96d7f81..7f021e6 100644
--- a/arch/arm/mach-imx/mach-mx21ads.c
+++ b/arch/arm/mach-imx/mach-mx21ads.c
@@ -67,7 +67,7 @@
 #define MX21ADS_IO_LED4_ON      0x4000
 #define MX21ADS_IO_LED3_ON      0x8000
 
-static unsigned int mx21ads_pins[] = {
+static const int mx21ads_pins[] __initconst = {
 
 	/* CS8900A */
 	(GPIO_PORTE | GPIO_GPIO | GPIO_IN | 11),