arm64: dts: mt8183-pumpkin: fix dtbs_check warning

Fix unit names to make dtbs_check happy.

Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>
Reviewed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Link: https://lore.kernel.org/r/20210414144643.17435-1-matthias.bgg@kernel.org
Link: https://lore.kernel.org/r/20210416143923.23406-2-matthias.bgg@kernel.org

'
Signed-off-by: Arnd Bergmann <arnd@arndb.de>