disp: msm: sde: fix dsc hw resource reservation

In atomic test phase DSC Hw block should be allowed to be reserved
without checking the mode information. Mode information is not
available before bridge enable is called and this results into dsc
not programmed very first mode set.

Change-Id: Ia9ec9a3c9387e34a8bb1d98ee6932aef8725bc8c
Signed-off-by: Abhijit Kulkarni <kabhijit@codeaurora.org>