drm/amd/display: explicitly disable psr_feature_enable appropriately

[Why]
If psr_feature_enable is set to true by default, it continues to be enabled
for non capable links.

[How]
explicitly disable the feature on links that are not capable of the same.

Fixes: 8c322309

 ("drm/amd/display: Enable PSR")
Signed-off-by: Shirish S <shirish.s@amd.com>
Reviewed-by: Leo Li <sunpeng.li@amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org # 5.15+