drm/panel: simple: Fix Innolux G070Y2-L01 BPP settings

The Innolux G070Y2-L01 supports two modes of operation:
1) FRC=Low/NC ... MEDIA_BUS_FMT_RGB666_1X7X3_SPWG ... BPP=6
2) FRC=High ..... MEDIA_BUS_FMT_RGB888_1X7X4_SPWG ... BPP=8

Currently the panel description mixes both, BPP from 1) and bus
format from 2), which triggers a warning at panel-simple.c:615.

Pick the later, set bpp=8, fix the warning.

Fixes: a5d2ade6

 ("drm/panel: simple: Add support for Innolux G070Y2-L01")
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Christoph Fritz <chf.fritz@googlemail.com>
Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Maxime Ripard <maxime@cerno.tech>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220220040718.532866-1-marex@denx.de
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>