According to the datasheet the allowed modes for the da9211
regulator are sync and auto mode. This should be changed in the
devicetree. This also fix an error message
'BUCKA: invalid regulator-allowed-modes element 0'
since value 0 is invalid.

Fixes: 689b937b ("arm64: dts: mediatek: add mt8173 elm and hana board")
Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
Tested-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Link: https://lore.kernel.org/r/20200903142819.24487-1-dafna.hirschfeld@collabora.comSigned-off-by: Matthias Brugger <matthias.bgg@gmail.com>