arm64: dts: hisilicon: write the values of property-units into a uint32 array

Use <> to separate the values of property-units will be treated as
multiple arrays. The errors similar to the following will be reported by
property-units.yaml.

ufs@ff3c0000: freq-table-hz: [[0, 0], [0, 0]] is too long

Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Wei Xu <xuwei5@hisilicon.com>