pinctrl: make the MSM SoC driver depend on OF

We had a compilation failure on x86_64 due to missing OF support
as this was an implicit dependency. Add an explicit dependency
on OF and OF_IRQ on the SoC driver.

Cc: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>