drm/amdgpu: Add reset function pointer for SDMA v4.4.2 page ring

This patch adds a reset function pointer to the SDMA v4.4.2 page ring
functionality. The new function pointer `reset` is set to
`sdma_v4_4_2_reset_queue`, which is responsible for resetting the SDMA queue.

Changes:
- Add `reset` function pointer to `sdma_v4_4_2_page_ring_funcs`.

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