gpio/mpc8xxx: add a const qualifier
gpio/mpc8xxx: add a const qualifier

This prepares *of_device_id.data becoming const. Without this change
the following warning would occur:

	drivers/gpio/gpio-mpc8xxx.c: In function 'mpc8xxx_add_controller':
	drivers/gpio/gpio-mpc8xxx.c:360:30: warning: assignment discards 'const' qualifier from pointer target type [enabled by default]

Acked-by: Linus Walleij <9cd9d802d23c0ed5e224beabf4ae4a5c478746ef@linaro.org>
Acked-by: Benjamin Herrenschmidt <a7089bb6e7e92505d88aaff006cbdd60cc9120b6@kernel.crashing.org>
Signed-off-by: Uwe Kleine-König <181323dd666a182bc2d953e52d0ac3ab54cd8391@pengutronix.de>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas