arm64: allwinner: Add compatible strings for clock devices used on both Allwinner H3 and H5

Allwinner H3 and H5 share many internal components, that's why they can
use the same drivers.
This patch adds the compatible strings to enable clock drivers
probing on Allwinner NanoPI NEO2 device.

Tested on: NanoPi NEO2 (by submitter), OrangePi PC2 (by manu)
Submitted by: Manuel Stühn (freebsdnewbie@freenet.de)
MFC after: 2 months
Differential Revision: https://reviews.freebsd.org/D20069