drm/msm/sde: enable pixel ext and qseed3 along with VIG

Pixel extension configuration is compulsory for vig pipes
on msmskunk and msm8998 target. If drm client does not provide
the pixel extension and qseed3 configuration, driver should
set the default values. Change sets the default values if
client is not configuring the blocks when VIG pipes are
selected.

Change-Id: I02f0e76fb87587d2eed9e5f4fcca5baa7d605b92
Signed-off-by: Gopikrishnaiah Anandan <agopik@codeaurora.org>
Signed-off-by: Dhaval Patel <pdhaval@codeaurora.org>