linux-phytec-fsl

gpio: drop surplus X86 dependencies

Port-mapped I/O depends on X86 already, so individual drivers need
not specify this dependency.

Suggested-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>