drm/panel: fix kernel-doc warning for devm_drm_panel_add()

drm/panel: fix kernel-doc warning for devm_drm_panel_add()

Use the correct kernel-doc notation for struct members to eliminate
kernel-doc warnings:

Warning: drivers/gpu/drm/drm_panel.c:119 function parameter 'dev'
 not described in 'devm_drm_panel_add'
Warning: drivers/gpu/drm/drm_panel.c:119 function parameter 'dev'
 not described in 'devm_drm_panel_add'

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202605210648.RI4ufD66-lkp@intel.com/
Signed-off-by: Dongyang Jin <jindongyang@kylinos.cn>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patch.msgid.link/20260521094545.3039207-1-jindongyang@kylinos.cn