input: touchscreen: st: add pinctrl config during suspend/resume

Add pinctrl mechanism to configure the state of GPIOs during
suspend and resume, for ST touch driver.

Change-Id: Ie41fab2ab61569f0393c868f3e5bbbe8eadaf686
Signed-off-by: Vevek Venkatesan <vevekv@codeaurora.org>