drm/dp: Revert "drm/dp: Introduce EDID-based quirks"

This reverts commit 0883ce81. Originally
these quirks were added because of the issues with using the eDP
backlight interfaces on certain laptop panels, which made it impossible
to properly probe for DPCD backlight support without having a whitelist
for panels that we know have working VESA backlight control interfaces
over DPCD. As well, it should be noted it was impossible to use the
normal sink OUI for recognizing these panels as none of them actually
filled out their OUIs, hence needing to resort to checking EDIDs.

At the time we weren't really sure why certain panels had issues with
DPCD backlight controls, but we eventually figured out that there was a
second interface that these problematic laptop panels actually did work
with and advertise properly: Intel's proprietary backlight interface for
HDR panels. So far the testing we've done hasn't brought any panels to
light that advertise this interface and don't support it properly, which
means we finally have a real solution to this problem.

As a result, we now have no need for the force DPCD backlight quirk, and
furthermore this also removes the need for any kind of EDID quirk
checking in DRM. So, let's just revert it for now since we were the only
driver using this.

v3:
* Rebase
v2:
* Fix indenting error picked up by checkpatch in
  intel_edp_init_connector()

Signed-off-by: Lyude Paul <lyude@redhat.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Cc: thaytan@noraisin.net
Cc: Vasily Khoruzhick <anarsoul@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210114221709.2261452-6-lyude@redhat.com