[media] media: davinci: vpbe: venc: move the enabling of vpss clocks to driver

The vpss clocks were enabled by calling a exported function from a driver
in a machine code. calling driver code from platform code is incorrect way.
This patch fixes this issue and calls the function from driver code itself.

Signed-off-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>