This reverts commit ca62297b.

Commit ca62297b ("drm/edid: Fix csync detailed mode parsing") fixed
EDID detailed mode sync parsing. Unfortunately, there are quite a few
displays out there that have bogus (zero) sync field that are broken by
the change. Zero means analog composite sync, which is not right for
digital displays, and the modes get rejected. Regardless, it used to
work, and it needs to continue to work. Revert the change.

Rejecting modes with analog composite sync was the part that fixed the
gitlab issue 8146 [1]. We'll need to get back to the drawing board with
that.

[1] https://gitlab.freedesktop.org/drm/intel/-/issues/8146

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/8789
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/8930
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/9044
Fixes: ca62297b ("drm/edid: Fix csync detailed mode parsing")
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: dri-devel@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v6.4+
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230815101907.2900768-1-jani.nikula@intel.com