mvebu: tidy up support for GL.iNet GL-MV1000

mvebu: tidy up support for GL.iNet GL-MV1000

This fixes a bunch of cosmetic issues with GL.iNet GL-MV1000:

- apply alphabetic sorting in multiple files
- use armada-3720 prefix for DTS like for other devices
- fix vendor capitalization for model in DTSes
- remove trivial comment in DTS files
- use DEVICE_VENDOR/DEVICE_MODEL
- remove redundant SUPPORTED_DEVICES
- use SOC instead of DEVICE_DTS
- remove empty line at EOF

Fixes: 050c24f05c85 ("mvebu: add support for GL.iNet GL-MV1000")
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>