synaptics_dsx: Fix manual fw updates

Clear the update-related memory structures after the automated
update run from boot, so that manual updates don't trip on incompatible
data

Change-Id: Ie7e637b65f93af0fb2ffecc97e48f253a04056ca
(cherry picked from commit a1a9176d68a9ffde8e64abec34f60932274a472e)