pinctrl: bcm63xx: fix unmet dependency on REGMAP for GPIO_REGMAP

pinctrl: bcm63xx: fix unmet dependency on REGMAP for GPIO_REGMAP

When PINCTRL_BCM63XX is selected,
and REGMAP is not selected,
Kbuild gives the following warning:

WARNING: unmet direct dependencies detected for GPIO_REGMAP
  Depends on [n]: GPIOLIB [=y] && REGMAP [=n]
  Selected by [y]:
  - PINCTRL_BCM63XX [=y] && PINCTRL [=y]

This is because PINCTRL_BCM63XX
selects GPIO_REGMAP without selecting or depending on
REGMAP, despite GPIO_REGMAP depending on REGMAP.

This unmet dependency bug was detected by Kismet,
a static analysis tool for Kconfig. Please advise
if this is not the appropriate solution.

Signed-off-by: Julian Braha <julianbraha@gmail.com>
Link: https://lore.kernel.org/r/20220117062557.89568-1-julianbraha@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>