buildconf: use downstream distro also for verdin-am62-k3r5

Assert that for both machines, verdin-am62 and verdin-am62-k3r5,
the downstream distro is set.
With adding the mainlinish U-Boot to the machine configuration that
now matters if use-head-next is set.
Without the change a bitbake build failure is seen when building
the SPL for verdin-am62-k3r5:

| Can't find default configuration "arch/../configs/verdin-am62_r5_defconfig"!

Reported-by: Emanuele Ghidoli <emanuele.ghidoli@toradex.com>
Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
(cherry picked from commit 8363ba48d2c3207a97974aec662b373692310b08)

0 files changed, 0 insertions, 0 deletions