msm: mdss: extend SW reset assert until VBIF halt is finished

If pipe is supposed to be halted using SW reset assert, extend
assert of SW reset until corresponding VBIF client is halted.

Change-Id: Iabe6a2c6302483fc9d14cedbd1480bb6c644597e
Signed-off-by: Ujwal Patel <ujwalp@codeaurora.org>