misc: ti-st: Update driver from omapzoom

Taken from http://omapzoom.org/?p=kernel/omap.git;a=tree;f=drivers/misc/ti-st;hb=645bb1ec3246cbdd39144e816fc31979c92b1e16

Change-Id: I0f6aad7a1a9492d6fb3320884182c250794300f6
Merge "misc: ti-st: Update driver from omapzoom" into cm-10.2