drm/amd/display: Update tiled to tiled copy command

[Why & How]
Tiled command rect dimensions is 1 based, do rect_x/y - 1 internally

Reviewed-by: Alvin Lee <alvin.lee2@amd.com>
Signed-off-by: Ostrowski Rafal <rostrows@amd.com>
Signed-off-by: Wayne Lin <wayne.lin@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>