pinctrl: msm: move all qualcomm drivers to subdir

We have four Qualcomm-related pin control drivers, and now there
are drivers coming in for the PMICs on these systems, so let's
create a qcom subdirectory to hold all the Qualcomm stuff.

Acked-by: Ivan T. Ivanov <iivanov@mm-sol.com>
Acked-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>