drm/amdgpu: add ring soft recovery v4

Instead of hammering hard on the GPU try a soft recovery first.

v2: reorder code a bit
v3: increase timeout to 10ms, increment GPU reset counter
v4: squash in compile fix (Christian)

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>