pinctrl: nomadik: fix warnings from unexported functions

There are five functions in the driver that are defined but
only used locally. Since these are not used in the current
kernel, delete them to avoid the following warnings:

drivers/pinctrl/nomadik/pinctrl-nomadik.c:1036:6: warning: symbol 'nmk_gpio_clocks_enable' was not declared. Should it be static?
drivers/pinctrl/nomadik/pinctrl-nomadik.c:1050:6: warning: symbol 'nmk_gpio_clocks_disable' was not declared. Should it be static?
drivers/pinctrl/nomadik/pinctrl-nomadik.c:1073:6: warning: symbol 'nmk_gpio_wakeups_suspend' was not declared. Should it be static?
drivers/pinctrl/nomadik/pinctrl-nomadik.c:1094:6: warning: symbol 'nmk_gpio_wakeups_resume' was not declared. Should it be static?
drivers/pinctrl/nomadik/pinctrl-nomadik.c:1120:6: warning: symbol 'nmk_gpio_read_pull' was not declared. Should it be static?

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>