drm/amd/amdgpu/jpeg_v1_0: Add some missing function param descriptions

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

 drivers/gpu/drm/amd/amdgpu/jpeg_v1_0.c:219: warning: Function parameter or member 'addr' not described in 'jpeg_v1_0_decode_ring_emit_fence'
 drivers/gpu/drm/amd/amdgpu/jpeg_v1_0.c:219: warning: Function parameter or member 'seq' not described in 'jpeg_v1_0_decode_ring_emit_fence'
 drivers/gpu/drm/amd/amdgpu/jpeg_v1_0.c:219: warning: Function parameter or member 'flags' not described in 'jpeg_v1_0_decode_ring_emit_fence'
 drivers/gpu/drm/amd/amdgpu/jpeg_v1_0.c:219: warning: Excess function parameter 'fence' description in 'jpeg_v1_0_decode_ring_emit_fence'
 drivers/gpu/drm/amd/amdgpu/jpeg_v1_0.c:293: warning: Function parameter or member 'job' not described in 'jpeg_v1_0_decode_ring_emit_ib'
 drivers/gpu/drm/amd/amdgpu/jpeg_v1_0.c:293: warning: Function parameter or member 'flags' not described in 'jpeg_v1_0_decode_ring_emit_ib'
 drivers/gpu/drm/amd/amdgpu/jpeg_v1_0.c:518: warning: Function parameter or member 'mode' not described in 'jpeg_v1_0_start'

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: Veerabadhran G <vegopala@amd.com>
Cc: amd-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>