ramips: correct vendor name for COMFAST/Joowin

When Joowin WR758AC V1 and V2 devices were added, they should have been
added with the primary manufacturer name which is COMFAST, since Joowin
is just an alternate vendor name on some coutries or stores.

Fix this by changing the the vendor name on the respective files and set
Joowin as ALT0 variants while ensuring compatibility for early users.
Also adjust the model names to better follow the naming rules.

As a side effect, fix mt76x8 network script which was left incorrectly
unsorted on the case block conditions.

Fixes: 766733e1 ("ramips: add support for Joowin WR758AC V1 and V2")
Signed-off-by: Rodrigo Araujo <araujo.rm@gmail.com>