media/cx231xx: Drop __TIME__ usage

The kernel already prints its build timestamp during boot, no need to
repeat it in random drivers and produce different object files each
time.

Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Cc: linux-media@vger.kernel.org
Signed-off-by: Michal Marek <mmarek@suse.cz>