drm/dp: Fix documentation warning

drm/dp: Fix documentation warning

It fixes the following warnings when
the kernel documentation is generated:

./include/drm/display/drm_dp_helper.h:126:
warning: Function parameter or struct member
'mode' not described in 'drm_dp_as_sdp'

./include/drm/display/drm_dp_helper.h:126:
warning: Excess struct member 'operation_mode'
description in 'drm_dp_as_sdp'

Signed-off-by: MarileneGarcia <marilene.agarcia@gmail.com>
Fixes: 0bbb8f594e33 ("drm/dp: Add Adaptive Sync SDP logging")
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Closes: https://lore.kernel.org/r/20240405141640.09b0bdbf@canb.auug.org.au
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240519031027.433751-1-marilene.agarcia@gmail.com