media: tvp5150: Add sync lock interrupt handling

This patch adds an optional interrupt handler to handle the sync
lock interrupt and sync lock status.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
[m.felsch@pengutronix.de: move added .g_std callback to separate patch]
Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>