- use P4 header for a waveshare ethernet phy module
- add --with-ethernet, --with-etherbone, --eth-ip, and --eth-dynamic-ip
target configuration options
- enable data_n outputs
- use drive_both property of updated VideoHDMIPHY to drive both
differential outputs
- adjust default clocking to successfully close timing
(sysclk at 50Mhz, HDMI at 25MHz, HDMIx5 at 125MHz)