librem5-devkit: Ship a devicetree with the upstream name

This will allow us to move flash-kernel to the upsteam name as well and
people upgrading to 5.x will get the right device tree with a recent
flash-kernel.

Since we also ship the old name here and in 5.x upgrades will also work
with older flash-kernel.

Signed-off-by: Guido Günther <guido.gunther@puri.sm>
2 jobs for next-dt in 30 minutes and 40 seconds (queued for 30 minutes and 55 seconds)
Status Job ID Name Coverage
  Build
passed #43960
librem5
build:aarch64:Image

00:30:40

passed #43961
librem5
build:aarch64:deb

00:21:39