drm/amdgpu: add patch to jpeg ring

Add patch commands to jepg ring by calling set patch ring function.

v2: remove modifications on max_dw, buf_mask and ptr_mask, since we are
now using extra_dw for jpeg ring.

Signed-off-by: Boyuan Zhang <boyuan.zhang@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>