gpio: dwapb: enable for Quark

The Intel Quark SoC contains the DW GPIO on board. While fixing the build error
the commit 1972c97d (gpio: dwapb: fix compile errors) disables the
possibility to build the driver on X86, i.e. Intel Quark.

The patch reenables it for Intel Quark as well.

Since we have Intel Quark SoC introduced in 4.0-rc1 I would like to make this
fix available there as well, though the actual MFD driver [1] is applied only
for next version.

[1] https://lkml.org/lkml/2015/2/1/217



Fixes: 1972c97d (gpio: dwapb: fix compile errors)
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>