pinctrl: msm: Add ability for drivers to supply a reserved GPIO list

When booting MSM based platforms with Device Tree or some ACPI
implementations, it is possible to provide a list of reserved pins
via the 'gpio-reserved-ranges' and 'gpios' properties respectively.
However some ACPI tables are not populated with this information,
thus it has to come from a knowledgable device driver instead.

Here we provide the MSM common driver with additional support to
parse this informtion and correctly populate the widely used
'valid_mask'.

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>