drm/amdgpu/vpe: add ring reset support

Implement ring reset for VPE.  Similar to VCN and JPEG,
just powergate the the IP to reset it.

v2: Properly set per queue reset flag

Reviewed-by: Jesse Zhang <jesse.zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>