arm: dts: hummingboard: add cubox/hummingboard DT (part 2 of 2)

These DT files are copied from kernel v5.3 with no changes.

This is part 2 of 2 commits. Included are DT files for SOM rev 1.5, and
Hummingboard2 Gate/Edge.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
22 files changed