ARM: 5685/1: Make MMCI driver compile without gpiolib

The recent addition of optional gpiolib support to check if a
card was inserted or write protected was really not optional.
It needs this ifdef to become optional so that U300 compiles,
for example.

Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>