drm/amd/pm/swsmu/smu11/vangogh_ppt: Provide a couple of missing parameter descriptions

drm/amd/pm/swsmu/smu11/vangogh_ppt: Provide a couple of missing parameter descriptions

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

 drivers/gpu/drm/amd/amdgpu/../pm/swsmu/smu11/vangogh_ppt.c:2381: warning: Function parameter or member 'residency' not described in 'vangogh_get_gfxoff_residency'
 drivers/gpu/drm/amd/amdgpu/../pm/swsmu/smu11/vangogh_ppt.c:2399: warning: Function parameter or member 'entrycount' not described in 'vangogh_get_gfxoff_entrycount'

Cc: Evan Quan <evan.quan@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
Cc: David Airlie <airlied@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Li Ma <li.ma@amd.com>
Cc: amd-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>