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

 drivers/gpu/drm/amd/amdgpu/../pm/powerplay/hwmgr/smu7_thermal.c:112: warning: Function parameter or member 'hwmgr' not described in 'smu7_fan_ctrl_set_static_mode'
 drivers/gpu/drm/amd/amdgpu/../pm/powerplay/hwmgr/smu7_thermal.c:112: warning: Function parameter or member 'mode' not described in 'smu7_fan_ctrl_set_static_mode'
 drivers/gpu/drm/amd/amdgpu/../pm/powerplay/hwmgr/smu7_thermal.c:137: warning: Function parameter or member 'hwmgr' not described in 'smu7_fan_ctrl_set_default_mode'
 drivers/gpu/drm/amd/amdgpu/../pm/powerplay/hwmgr/smu7_thermal.c:209: warning: Function parameter or member 'hwmgr' not described in 'smu7_fan_ctrl_set_fan_speed_percent'
 drivers/gpu/drm/amd/amdgpu/../pm/powerplay/hwmgr/smu7_thermal.c:209: warning: Function parameter or member 'speed' not described in 'smu7_fan_ctrl_set_fan_speed_percent'
 drivers/gpu/drm/amd/amdgpu/../pm/powerplay/hwmgr/smu7_thermal.c:245: warning: Function parameter or member 'hwmgr' not described in 'smu7_fan_ctrl_reset_fan_speed_to_default'
 drivers/gpu/drm/amd/amdgpu/../pm/powerplay/hwmgr/smu7_thermal.c:268: warning: Function parameter or member 'hwmgr' not described in 'smu7_fan_ctrl_set_fan_speed_rpm'
 drivers/gpu/drm/amd/amdgpu/../pm/powerplay/hwmgr/smu7_thermal.c:268: warning: Function parameter or member 'speed' not described in 'smu7_fan_ctrl_set_fan_speed_rpm'
 drivers/gpu/drm/amd/amdgpu/../pm/powerplay/hwmgr/smu7_thermal.c:299: warning: Function parameter or member 'hwmgr' not described in 'smu7_thermal_get_temperature'
 drivers/gpu/drm/amd/amdgpu/../pm/powerplay/hwmgr/smu7_thermal.c:325: warning: Function parameter or member 'hwmgr' not described in 'smu7_thermal_set_temperature_range'
 drivers/gpu/drm/amd/amdgpu/../pm/powerplay/hwmgr/smu7_thermal.c:325: warning: Function parameter or member 'low_temp' not described in 'smu7_thermal_set_temperature_range'
 drivers/gpu/drm/amd/amdgpu/../pm/powerplay/hwmgr/smu7_thermal.c:325: warning: Function parameter or member 'high_temp' not described in 'smu7_thermal_set_temperature_range'
 drivers/gpu/drm/amd/amdgpu/../pm/powerplay/hwmgr/smu7_thermal.c:358: warning: Function parameter or member 'hwmgr' not described in 'smu7_thermal_initialize'
 drivers/gpu/drm/amd/amdgpu/../pm/powerplay/hwmgr/smu7_thermal.c:377: warning: Function parameter or member 'hwmgr' not described in 'smu7_thermal_enable_alert'
 drivers/gpu/drm/amd/amdgpu/../pm/powerplay/hwmgr/smu7_thermal.c:395: warning: Function parameter or member 'hwmgr' not described in 'smu7_thermal_disable_alert'
 drivers/gpu/drm/amd/amdgpu/../pm/powerplay/hwmgr/smu7_thermal.c:414: warning: Function parameter or member 'hwmgr' not described in 'smu7_thermal_stop_thermal_controller'
 drivers/gpu/drm/amd/amdgpu/../pm/powerplay/hwmgr/smu7_thermal.c:433: warning: Function parameter or member 'hwmgr' not described in 'smu7_thermal_start_smc_fan_control'

Cc: Evan Quan <evan.quan@amd.com>
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: 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>