drm: adv7511: Add max_lane_freq_khz variable to struct adv7511_chip_info

The ADV7533 supports a maximum lane clock of 800MHz whereas it is 891MHz
for ADV7535. Add max_lane_freq_khz variable to struct adv7511_chip_info to
handle this difference.

While at it, drop the unused local variable max_lane_freq.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Robert Foss <rfoss@kernel.org>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230830142358.275459-4-biju.das.jz@bp.renesas.com