soc: fsl: qe: Change GPIO driver to a proper platform driver

soc: fsl: qe: Change GPIO driver to a proper platform driver

In order to be able to add interrupts to the GPIOs, first change the
QE GPIO driver to the proper platform driver in order to allow
initialisation to be done in the right order, otherwise the GPIOs
get added before the interrupts are registered.

Remove linux/of.h and linux/property.h which are unused.

And to improve readability and reduce risk of errors, add a macro to
transform a pin number into the mask that matches the associated bit
in registers.

Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Link: https://lore.kernel.org/r/b0b4480255569c7f0dfe58854a444f9a40da6681.1758212309.git.christophe.leroy@csgroup.eu
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>