pinctrl: qcom: spmi-mpp: Add PM/PMI8950 compatible strings

PM8950 and PMI8950 have four MPPs and this driver is compatible.

Signed-off-by: AngeloGioacchino Del Regno <kholk11@gmail.com>
Link: https://lore.kernel.org/r/20191031103507.30678-4-kholk11@gmail.com


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>