input: touchscreen: synaptics_tcm: defer probe if panel not found

In many cases display panel information may not be available when the
touch driver is being probed. This change defers the probe if the
panel is not found to ensure that the correct touch driver is probed.

Change-Id: I52b8cd49342b6213639eefb8f10876178612af49
Signed-off-by: Ritesh Kumar <riteshk@codeaurora.org>