doc: board: phytec: Add phyCORE-AM62ax

Add documentation for PHYTEC phyCORE-AM62ax SoM.

Signed-off-by: Garrett Giordano <ggiordano@phytec.com>
Reviewed-by: Wadim Egorov <w.egorov@phytec.de>
Reviewed-by: Dhruva Gole <d-gole@ti.com>
3 files changed