input: touchscreen: atmel_mxt_ts: Add dummy read after reset

Fix the initialization sequence to do a dummy read after the soft
reset.

Change-Id: I65ac3e37328182011ab0916654474c5f6711ec98
Signed-off-by: Colin Cross <ccross@android.com>

Conflicts:
	drivers/input/touchscreen/atmel_mxt_ts.c