Fixes the following W=1 kernel build warning(s):

 drivers/gpu/drm/amd/amdgpu/uvd_v6_0.c:211: warning: Function parameter or member 'bo' not described in 'uvd_v6_0_enc_get_create_msg'
 drivers/gpu/drm/amd/amdgpu/uvd_v6_0.c:211: warning: Excess function parameter 'adev' description in 'uvd_v6_0_enc_get_create_msg'
 drivers/gpu/drm/amd/amdgpu/uvd_v6_0.c:275: warning: Function parameter or member 'bo' not described in 'uvd_v6_0_enc_get_destroy_msg'
 drivers/gpu/drm/amd/amdgpu/uvd_v6_0.c:275: warning: Excess function parameter 'adev' description in 'uvd_v6_0_enc_get_destroy_msg'
 drivers/gpu/drm/amd/amdgpu/uvd_v6_0.c:332: warning: Function parameter or member 'timeout' not described in 'uvd_v6_0_enc_ring_test_ib'
 drivers/gpu/drm/amd/amdgpu/uvd_v6_0.c:472: warning: Function parameter or member 'handle' not described in 'uvd_v6_0_hw_init'
 drivers/gpu/drm/amd/amdgpu/uvd_v6_0.c:472: warning: Excess function parameter 'adev' description in 'uvd_v6_0_hw_init'
 drivers/gpu/drm/amd/amdgpu/uvd_v6_0.c:541: warning: Function parameter or member 'handle' not described in 'uvd_v6_0_hw_fini'
 drivers/gpu/drm/amd/amdgpu/uvd_v6_0.c:541: warning: Excess function parameter 'adev' description in 'uvd_v6_0_hw_fini'
 drivers/gpu/drm/amd/amdgpu/uvd_v6_0.c:900: warning: Function parameter or member 'addr' not described in 'uvd_v6_0_ring_emit_fence'
 drivers/gpu/drm/amd/amdgpu/uvd_v6_0.c:900: warning: Function parameter or member 'seq' not described in 'uvd_v6_0_ring_emit_fence'
 drivers/gpu/drm/amd/amdgpu/uvd_v6_0.c:900: warning: Function parameter or member 'flags' not described in 'uvd_v6_0_ring_emit_fence'
 drivers/gpu/drm/amd/amdgpu/uvd_v6_0.c:900: warning: Excess function parameter 'fence' description in 'uvd_v6_0_ring_emit_fence'
 drivers/gpu/drm/amd/amdgpu/uvd_v6_0.c:930: warning: Function parameter or member 'addr' not described in 'uvd_v6_0_enc_ring_emit_fence'
 drivers/gpu/drm/amd/amdgpu/uvd_v6_0.c:930: warning: Function parameter or member 'seq' not described in 'uvd_v6_0_enc_ring_emit_fence'
 drivers/gpu/drm/amd/amdgpu/uvd_v6_0.c:930: warning: Function parameter or member 'flags' not described in 'uvd_v6_0_enc_ring_emit_fence'
 drivers/gpu/drm/amd/amdgpu/uvd_v6_0.c:930: warning: Excess function parameter 'fence' description in 'uvd_v6_0_enc_ring_emit_fence'
 drivers/gpu/drm/amd/amdgpu/uvd_v6_0.c:997: warning: Function parameter or member 'job' not described in 'uvd_v6_0_ring_emit_ib'
 drivers/gpu/drm/amd/amdgpu/uvd_v6_0.c:997: warning: Function parameter or member 'flags' not described in 'uvd_v6_0_ring_emit_ib'
 drivers/gpu/drm/amd/amdgpu/uvd_v6_0.c:1023: warning: Function parameter or member 'job' not described in 'uvd_v6_0_enc_ring_emit_ib'
 drivers/gpu/drm/amd/amdgpu/uvd_v6_0.c:1023: warning: Function parameter or member 'flags' not described in 'uvd_v6_0_enc_ring_emit_ib'

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: amd-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Cc: linux-media@vger.kernel.org
Cc: linaro-mm-sig@lists.linaro.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>