drm/msm: a5xx: Remove unneeded parens

A small fixup I posted with my v2 patch [1] that was dropped.

[1]- https://lists.freedesktop.org/archives/freedreno/2018-October/003647.html



Signed-off-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>