drm/bridge: lt8912b: use drm_bridge_edid_read()

drm/bridge: lt8912b: use drm_bridge_edid_read()

[ Upstream commit 60d1fe1a7f302cc1151b155ac2d134db59bb1420 ]

Prefer using the struct drm_edid based functions.

cc: Adrien Grassein <adrien.grassein@gmail.com>
Cc: Andrzej Hajda <andrzej.hajda@intel.com>
Cc: Neil Armstrong <neil.armstrong@linaro.org>
Cc: Robert Foss <rfoss@kernel.org>
Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Jonas Karlman <jonas@kwiboo.se>
Cc: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/32c9b52fe6fa7cbad6bfd0ff00041876977e02ea.1706038510.git.jani.nikula@intel.com
Stable-dep-of: 171b711b26cc ("drm/bridge: lt8912b: do not return negative values from .get_modes()")
Signed-off-by: Sasha Levin <sashal@kernel.org>