Add 38400 GPS baud option

[FoxKyong]

Summary

This PR adds 38400 as a selectable GPS baud rate.

Some T-Deck Plus units with u-blox GNSS modules use 38400 baud by default. The current fixed baud rate list only contains 4800, 9600 and 19200, with AUTO at index 3, so 38400 cannot be selected from the GUI.

Changes

• Add 38400 to GPS_BAUD[]
• Move AUTO baud index from 3 to 4
• Add 38400 to the GPS Speed dropdown
• Set gpsBaudDetected when a fixed baud rate is selected, so the info command reports the active baud rate correctly
• Keep AUTO as the default value

Tested on

• Device: LilyGO T-Deck Plus
• Environment: TDECK_ESP32S3
• GPS baud: 38400
• GPS update rate: 1 Hz

Test result

With 38400 selected:

• NMEA parsing works
• Parse OK increases continuously
• CRC Errors remains 0
• GNSS gets a 3D fix

Index mapping after this change

0 = 4800
1 = 9600
2 = 19200
3 = 38400
4 = AUTO

[jgauchia]

I need to review GPS_BAUD_PCAS , because this only applies to AT6558D modules and maybe 38400 baud isn't available

[jgauchia]

I'll include this PR in the next release , planned to be at end of June.

[FoxKyong]

Thanks

[jgauchia]

Thanks

Thanks to you!,
I hope that my little project you like it.