drm/amd/display: Change default driver setting for "Force ODM2:1 for eDP" policy

drm/amd/display: Change default driver setting for "Force ODM2:1 for eDP" policy

[Why & How]
Change the driver setting: force single eDP ODM2:1 disable as default.
Still allow user to enable it via debug option.

Revert to unblock testing.

Reviewed-by: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: Ovidiu Bunea <ovidiu.bunea@amd.com>
Signed-off-by: Ray Wu <ray.wu@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>