drivers: gpio-uclass: support PMIC GPIO children

UCLASS_PMIC may have GPIO children without exposed fdt node,
in this case if requesting fails, check if uclass is PMIC.

Restrict build for supported devices only to save those precious
bytes on devices with no spare memory.

Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
1 file changed