Add Portwell Neptune machine

Initial introduction of Portwell Neptune family equipped with
Aspeed 2500 BMC SoC.

Tested: Build portwell neptune board and load on the target hardware.
Ensure that BMC boots to console.

Change-Id: I7a97162dfe3031904e27f2de2691e693079c9216
Signed-off-by: Amithash Prasad <amithash@fb.com>
8 files changed
tree: 7f645ba5e7965bdf1109cebddfc090830a59bc5c
  1. meta-neptune/