pinctrl: qcom: spmi-gpio: Update GPIO EN_CTL when setting pin config

GPIO is expected to be disabled iff PIN_CONFIG_BIAS_HIGH_IMPEDANCE is
configured. Update is_enabled flag in config_set() so that it can
reflect GPIO status correctly. Also modify EN_CTL register based on
is_enabled flag in config_set() to configure the GPIO properly.

Signed-off-by: Fenglin Wu <fenglinw@codeaurora.org>
Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>