pinctrl: qcom-spmi-gpio: Fix output type configuration

GPIO output type configuration was incorrectly overwritten
by strength value. Fix this.

Signed-off-by: Ivan T. Ivanov <ivan.ivanov@linaro.org>
Acked-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>