pinctrl: stm32: handle semaphore acquisition when handling pinctrl/pinmux

pinctrl: stm32: handle semaphore acquisition when handling pinctrl/pinmux

When a GPIO RIF configuration is in semaphore mode, and the semaphore
hasn't been taken before configuring the GPIO, the write operations
silently fail.

To avoid a silent fail when applying a pinctrl, if the pins that are
being configured are in semaphore mode, take the semaphore. Note that
there is no proper release of the RIF semaphore yet for pinctrl.

Signed-off-by: Gatien Chevallier <gatien.chevallier@foss.st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>