drm/amdgpu: add function parameter description in 'amdgpu_device_set_cg_state'

Fixes gcc warning:

drivers/gpu/drm/amd/amdgpu/amdgpu_device.c:1954: warning: Function
parameter or member 'state' not described in 'amdgpu_device_set_cg_state'

Fixes: e3ecdffa ("drm/amdgpu: add documentation for amdgpu_device.c")
Signed-off-by: yu kuai <yukuai3@huawei.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_device.c

@@ -1936,6 +1936,7 @@ static bool amdgpu_device_check_vram_lost(struct amdgpu_device *adev)
  * amdgpu_device_set_cg_state - set clockgating for amdgpu device
  *
  * @adev: amdgpu_device pointer
+ * @state: clockgating state (gate or ungate)
  *
  * The list of all the hardware IPs that make up the asic is walked and the
  * set_clockgating_state callbacks are run.