[MeshOS 1.0.10] add configuration option for GPS

[cfojtzik]

Add a possibility to set GPS Baud-Rate on MeshOS, to get GPS on OG T-Deck working.

[dreirund]

On MeshOS 1.0.10 I get a GPS fix on a LilyGo T-Deck.

[cfojtzik]

Using /gps baud in Terminal fixed it for me, thanks for implementing!