gpio: mxs: remove __init annotation

Building with an old toolchain, I ran into this warning:

WARNING: vmlinux.o(.text+0x63eef0): Section mismatch in reference
  from the function mxs_gpio_probe() to the function
  .init.text:mxs_gpio_init_gc()

Clearly the annotation is wrong, since the function is called from the
non-init probe, so let's remove it.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-mxs.c

@@ -205,7 +205,7 @@ static int mxs_gpio_set_wake_irq(struct irq_data *d, unsigned int enable)
 	return 0;
 }
 
-static int __init mxs_gpio_init_gc(struct mxs_gpio_port *port, int irq_base)
+static int mxs_gpio_init_gc(struct mxs_gpio_port *port, int irq_base)
 {
 	struct irq_chip_generic *gc;
 	struct irq_chip_type *ct;