arm64: dts: marvell: use new bindings for xor clocks on ap806

New bindings are used for the system controller on the ap806, which
means all clock properties must be converted. Use the new bindings in
the xor nodes.

Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>