msm: mdss: install the rel_fence even if retire_fence is skipped

Whenever retire_fence was skipped, the rel_fence was incorrectly
skipped as well. Ensure the rel_fence is installed even if the
retire_fence was skipped.

Bug: 32402303
Change-Id: I9e6af8c7d91e514ab5ed780a5643f4dbebf66756