m68k: do away with ARCH_REQUIRE_GPIOLIB

Replace "select ARCH_REQUIRE_GPIOLIB" with "select GPIOLIB"
as this can now be selected directly.

Cc: Michael Büsch <m@bues.ch>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: linux-m68k@lists.linux-m68k.org
Acked-by: Greg Ungerer <gerg@linux-m68k.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>