boards: beagle: add BeaglePlay on-board CC1352P7

Add support for BeaglePlay, a TI AM6254 SoC based development board with a
CC1352P7 wireless microcontroller for supporting software defined 2.4GHz
and SubGHz wireless protocols. Support for running Zephyr on the
quad-A53 SoC or the programmable M4 on the SoC would be provided
separately.

See https://beagleplay.org

 for details.

Signed-off-by: Jason Kridner <jkridner@beagleboard.org>
Signed-off-by: Ayush Singh <ayush@beagleboard.org>