Add support for LoRa E5 Dev Board

[nobodywasishere]

Closes #596. Can be squashed.

[egnor]

I am excited for this change! Anyone we need to ping to take a look?

[si2w]

I tried to use the arduino framework on the board. I added arduino in the frameworks :

"frameworks": [
    "arduino",
	  "cmsis",
    "stm32cube",
    "zephyr"
  ],

But it seems that some files are missing :
: fatal error: variant_LORA_E5_DEV_BOARD.h: No such file or directory

Could you help ?

Thanks

[nobodywasishere]

For arduino, it looks like there needs to be board specific files added to the stm32duino framework, for example, like the other ones listed here.

[si2w]

you mean, just copy the directory or adapt them to the lora-e5-dev-board ? If I need to adapt the files, are you aware of a tutorial to do so ? Thanks for your quick response

[valeros]

Thanks for the PR, merged.

[si2w]

Thanks for the merge