V4L/DVB: V4L: tvp514x: Add Powerup sequence during s_input to lock the signal properly

For the sequence streamon -> streamoff and again s_input, it fails
to lock the signal, since streamoff puts TVP514x into power off state
which leads to failure in sub-sequent s_input.

So add powerup sequence in s_routing (if disabled), since it is
important to lock the signal at this stage.

Signed-off-by: Vaibhav Hiremath <hvaibhav@ti.com>
Signed-off-by: Sudhakar Rajashekhara <sudhakar.raj@ti.com>
Signed-off-by: Muralidharan Karicheri <mkaricheri@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>