dts: bindings: update vendor-prefixes.txt

Update our vendor-prefixes.txt file to match the data in upstream
Linux's vendor-prefixes.yaml file as of Linux commit
8ac91e6c6033ebc12c5c1e4aa171b81a662bd70f.

(We can't easily switch to using the Linux YAML file directly because
our documentation tooling depends on this plain text format.)

The changes were done using a script and then cleaned up by hand in
order to not throw away any Zephyr-only prefixes, and to manually
override Linux in some cases.

List of Zephyr-only prefixes, all of which were kept:

    asmedia
    cadence
    gaisler
    lairdconnect
    ovti
    openisa
    particle
    quicklogic
    ruuvi
    segger
    vnd
    weact
    zephyr

Other things to note:

- keep Espressif as 'espressif', overriding Linux's 'esp'
- 'gw' is deprecated in Linux and is unused here; just remove it
- ROCKTECH DISPLAYS LIMITED SHOULD HAVE BEEN ALL CAPS;
  HOW COULD WE POSSIBLY HAVE MISSED THIS BEFORE?
- Did not include '70mai' from upstream, as that violates the legal
  compatible regexp

Signed-off-by: Martí Bolívar <marti.bolivar@nordicsemi.no>