drm/amd/display: Cover crtc vblank IPS self-refresh restore

Add dm_test_crtc_enable_vblank_ips_restore to cover the IPS/self-refresh
branch of amdgpu_dm_crtc_set_vblank() that calls drm_crtc_vblank_restore().

The test primes the DC with ips_support set and IPS not fully disabled, a
supported PSR version (self-refresh supported) and an immediate-disable
vblank config, so all four conditions gating the restore hold. A stub
get_vblank_timestamp hook is installed on the CRTC so the restore helper
passes its sanity check, and the enable path then runs to completion.

Assisted-by: Copilot:Claude-Opus-4.8
Reviewed-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Bhawanpreet Lakha <bhawanpreet.lakha@amd.com>
Signed-off-by: Roman Li <roman.li@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

0 files changed, 0 insertions, 0 deletions