panel-simple: add Innolux N125HCE-GN1

The Innolux N125HCE-GN1 display is used in the MNT Reform 2.0 laptop,
attached via eDP to a SN65DSI86 MIPI-DSI to eDP bridge.

Signed-off-by: Lukas F. Hartmann <lukas@mntre.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20201124172604.981746-1-lukas@mntre.com