ARM: mxs/tx28: convert to new leds-gpio registration helper

This allows to move the led definition to .init.rodata.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
diff --git a/arch/arm/mach-mxs/Kconfig b/arch/arm/mach-mxs/Kconfig
index f114960..162b0b0 100644
--- a/arch/arm/mach-mxs/Kconfig
+++ b/arch/arm/mach-mxs/Kconfig
@@ -55,6 +55,7 @@
 config MODULE_TX28
 	bool
 	select SOC_IMX28
+	select LEDS_GPIO_REGISTER
 	select MXS_HAVE_AMBA_DUART
 	select MXS_HAVE_PLATFORM_AUART
 	select MXS_HAVE_PLATFORM_FEC