msm: tsc: update pinctrl support

Update the implementation of the pinctrl usage in the driver such
that the driver can use several groups of pins simultaneously, as
required by the TSC HW.

Change-Id: I9d3350a183c47d4eca9a0628ab17fa55fff2fb06
Signed-off-by: Anat Etzion-Fuchs <aetzion@codeaurora.org>