drm/amdgpu/uvd3.1: Don't validate the firmware when already validated

drm/amdgpu/uvd3.1: Don't validate the firmware when already validated

UVD 3.1 firmware validation seems to always fail after
attempting it when it had already been validated.
(This works similarly with the VCE 1.0 as well.)

Don't attempt repeating the validation when it's already done.

This caused issues in situations when the system isn't able
to suspend the GPU properly and so the GPU isn't actually
powered down. Then amdgpu would fail when calling the IP
block resume function.

Closes: https://gitlab.freedesktop.org/drm/amd/-/work_items/2887
Fixes: bb7978111dd3 ("drm/amdgpu: fix SI UVD firmware validate resume fail")
Signed-off-by: Timur Kristóf <timur.kristof@gmail.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 889a2cfd889c4a4dd9d0c89ce9a8e60b78be71dd)