Change config.txt to resolve HDMI resolution issue on Raspberry Pi.

[1] https://www.raspberrypi.org/documentation/configuration/config-txt.md

HDMI_IGNORE_EDID

Setting this to 0xa5000080 enables the ignoring of EDID/display data if your display doesn't have an accurate EDID. It requires this unusual value to ensure that it doesn't get triggered accidentally.