Add support for Catena 4630, 4617 and 4618

[dhineshkumarmcci]

Need to add platform support for Catena 4630.

[dhineshkumarmcci]

Added support for Catena 4630 under branch issue135.

[terrillmoore]

Don't forget that you must add entries to .travis.yml here, and in the other libraries (arduino-lmic and arduino-lorawan), to confirm that the libraries compile with the BSP.

[dhineshkumarmcci]

Also added to add support for Catena 4617 and 4618 ( issue #173 ) in this push.