drm/amdgpu: Change kiq ring initialize sequence on gfx9

drm/amdgpu: Change kiq ring initialize sequence on gfx9

1. initialize kiq before initialize gfx ring.
2. set kiq ring ready immediately when kiq initialize
   successfully.
3. split function gfx_v9_0_kiq_resume into two functions.
     gfx_v9_0_kiq_resume is for kiq initialize.
     gfx_v9_0_kcq_resume is for kcq initialize.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Rex Zhu <Rex.Zhu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>