zirc: display: qpic: enable qpic interface clock

Enable qpic interface clock for register accessing,
always use the resolution set by device tree, send
display off command to panel before turning off power.

Change-Id: Ia0e098f303ce2e9e710644a4c6921ff7f5fcfc49
Signed-off-by: Ken Zhang <kenz@codeaurora.org>