arm64: dts: hisi: add hns-dsaf cpld control for the hip07 SoC

Add cpld-syscon node to support the cpld control for hns-dsaf
on the hip07 SoC.

Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: Wei Xu <xuwei5@hisilicon.com>