This GPIO controller is a part of Intel MID platforms which are somehow
different to pure PCs. Thus, there is no need that driver is compiled for them.

Replace dependency to X86_INTEL_MID.

While here, fix capitalization of MID abbreviation.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>