drm/amd: Re-enable common modes for eDP and LVDS

drm/amd: Re-enable common modes for eDP and LVDS

[Why]
Although compositors will add their own modes, Xorg won't use it's own
modes and will only stick to modes advertised by the driver. This mean a
user that used to pick 1024x768 could no longer access it unless the
panel's native resolution was 1024x768.

[How]
Revert commit 6d396e7ac1ce3 ("drm/amd/display: Disable common modes for
LVDS") and commit 7948afb46af92 ("drm/amd/display: Disable common modes
for eDP").

The panel will still use scaling for any non-native modes due to
commit 978fa2f6d0b12 ("drm/amd/display: Use scaling for non-native
resolutions on eDP")

Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4538
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://lore.kernel.org/r/20250828140856.2887993-1-superm1@kernel.org
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit c2fbf72fe3c2d08856e834ca43328a8829a261d8)