[Arm-netbook] EOMA68-A20 interface redesign

[Luke Kenneth Casson Leighton]

https://www.skhynix.com/products/computing/view.jsp?info.ramKind=19&info.serialNo=H5TQ4G83BFR

ok i've done the interface redesign which i will document properly
later: SATA is gone, 2nd USB is in, i added one EINT and the 4th pin
is a VREF output for GPIO and UART voltage levels.

i also noticed that hynix do a 4gbit x8 RAM chip which is
pin-compatible with the H5TQ2G83BFR, so i *think* we can go to 2gbyte
of RAM.

thoughts?

l.