xtensa: add support for the XTFPGA boards

The Avnet LX60/LX110/LX200 board is an FPGA board that can be configured with
an Xtensa processor and an OpenCores Ethernet device.

Signed-off-by: Chris Zankel <chris@zankel.net>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>
9 files changed