Mark Haslinghuis

@ctzsnooze please add some explanation or documentation.

@hydra please rebase

Closing as stale.

Besides rebase build is failing so needs some work after merge of https://github.com/betaflight/betaflight/pull/11786 G4 samples are on their way for development.

@DieHertz hope you don't mind. Have rebased this work and fixed the macro for non LPUART boards

`LPUART` is showing but `SOFTSERIAL` not.

On MAMBAG4: 

For 4.4 we need: https://github.com/betaflight/unified-targets/pull/989 For 4.5 we need: https://github.com/betaflight/betaflight/pull/12705

> This PR contains changes from https://github.com/betaflight/betaflight/pull/11786 as it's somewhat related (touches the same places), I will remove them once it's merged. @KarateBrot @SteveCEvans please review #11786

@ctzsnooze this has nothing to do with this PR. Rename was done in #12679 but only applies to config.h. Before that it was changed from SERIAL to UART.