drm/amd/display: Apply vactive dram clock change workaround to dcn2 DMLv2

[Why]
This workaround was put in dcn2 DMLv1, and now we need it in DMLv2.

Signed-off-by: Joshua Aberback <joshua.aberback@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>