pinctrl: qcom: sdm845: Provide ACPI support

This patch provides basic support for booting with ACPI instead
of the currently supported Device Tree.  When doing so there are a
couple of differences which we need to taken into consideration.

Firstly, the SDM850 ACPI tables omit information pertaining to the
4 reserved GPIOs on the platform.  If Linux attempts to touch/
initialise any of these lines, the firmware will restart the
platform.

Secondly, when booting with ACPI, it is expected that the firmware
will set-up things like; Regulators, Clocks, Pin Functions, etc in
their ideal configuration.  Thus, the possible Pin Functions
available to this platform are not advertised when providing the
higher GPIOD/Pinctrl APIs with pin information.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>