drm/amdgpu/sdma7: set sdma hang watchdog

Set SDMAx_WATCHDOG_CNTL.QUEUE_HANG_COUNT registers
to improve SDMA reliability.

Signed-off-by: Jack Xiao <Jack.Xiao@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>