ARM: 6347/2: nomadik: move nmk_gpio_probe to .devinit.text

This fixes a section mismatch reported by modpost:

	WARNING: arch/arm/plat-nomadik/built-in.o(.data+0x100): Section mismatch in reference from the variable nmk_gpio_driver to the function .init.text:nmk_gpio_probe()
	The variable nmk_gpio_driver references
	the function __init nmk_gpio_probe()
	If the reference is valid then annotate the
	variable with __init* or __refdata (see linux/init.h) or name the variable:
	*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console,

According to Rabin VINCENT the alternative to use platform_driver_probe
won't work because the "platform devices are not yet registered when
nmk_gpio_init() is called."

Acked-by: Rabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>