amd/pademelon has push to https://github.com/BTDC/coreboot

[WANG Siyuan]

Hi, all
AMD has a low cost Carrizo board pademelon. We brought it up. The serial
port works. But we don't test every feature.
I push code to https://github.com/BTDC/coreboot , branch pademelon.
src/mainboard/amd/ipc_fp4_lc is the mainboard code. I named it ipc_fp4_lc.
I hope this is useful.