ARM: npcm: Bring back GPIOLIB support

The CONFIG_ARCH_REQUIRE_GPIOLIB is gone since commit 65053e1a
("gpio: delete ARCH_[WANTS_OPTIONAL|REQUIRE]_GPIOLIB") and all platforms
should explicitly select GPIOLIB to have it.

Link: https://lore.kernel.org/r/20200130195525.4525-1-krzk@kernel.org
Cc: <stable@vger.kernel.org>
Fixes: 65053e1a

 ("gpio: delete ARCH_[WANTS_OPTIONAL|REQUIRE]_GPIOLIB")
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Olof Johansson <olof@lixom.net>