allwinner: extend support for H5 (sun50i-h5)

[TzeWey]

What kind of new feature are you looking for? (Keep the one that applies, please describe)

• Hardware: Allwinner H5, NanoPi NEO Core2
• Software: new CPU support

Do you plan to:

• Contribute an initial driver: Yes
• Write unit tests: No
• Update https://github.com/periph/cmd to use the new functionality: No