pinctrl: mediatek: Fix multiple registration issue.

pinctrl: mediatek: Fix multiple registration issue.

commit d48c2c02645392483f2b88b050d21ce1db6997b3 upstream.

Since our common driver need support main chip and PMU
at the same time, that means it will register two
pinctrl device, and the pinctrl_desc structure should
be used two times.

But pinctrl_desc use global static definition, then
the latest registered pinctrl device will overwrite
the old one's, all members in pinctrl_desc will set to
the new one's, such as name, pins and pins numbers, etc.
This is a bug.

Move pinctrl_desc into mtk_pinctrl, assign new value for
each pinctrl device to fix it.

Signed-off-by: Hongzhou Yang <hongzhou.yang@mediatek.com>
Reviewed-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>