drm/amd/display: Use PSR version selected during set_psr_caps

[Why]
If the DPCD caps specifies a PSR version newer than PSR_VERSION_1 then
we fallback to using PSR_VERSION_1 in amdgpu_dm_set_psr_caps.

This gets overriden with the raw DPCD value in amdgpu_dm_link_setup_psr,
which can result in DMCUB hanging if we pass in an unsupported PSR
version number.

[How]
Fix the hang by using link->psr_settings.psr_version directly during
amdgpu_dm_link_setup_psr.

Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Reviewed-by: Anthony Koo <Anthony.Koo@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>