drm/amd/display: cursor update command incomplete

Missing send cursor_rect width & Height into DMUB. PSR-SU would use
these information. But missing these assignment in last refactor commit

Tested-by: Mark Broadworth <mark.broadworth@amd.com>
Reviewed-by: Anthony Koo <Anthony.Koo@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Max Tseng <max.tseng@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>