pinctrl: qcom: delete pin_config_get/set pinconf operations

The .pin_config_get/set operation are not supported in qcom pinctrl
driver. As the pinconf core is smart enough it doesn't complain
about that.

Signed-off-by: Stanimir Varbanov <svarbanov@mm-sol.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>