ARM: imx: get rid of mxc_gpio_init

This function is defined once for each imx family and so is in the way
when compiling a kernel for more than one SoC.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
diff --git a/arch/arm/mach-imx/mm-imx21.c b/arch/arm/mach-imx/mm-imx21.c
index 115c212..68aa5d2 100644
--- a/arch/arm/mach-imx/mm-imx21.c
+++ b/arch/arm/mach-imx/mm-imx21.c
@@ -77,7 +77,10 @@
 	iotable_init(imx21_io_desc, ARRAY_SIZE(imx21_io_desc));
 }
 
+int imx21_register_gpios(void);
+
 void __init mx21_init_irq(void)
 {
+	imx21_register_gpios();
 	mxc_init_irq(MX21_IO_ADDRESS(MX21_AVIC_BASE_ADDR));
 }