Port to the really neat 68010 based board at https://rosco-m68k.com/
Port Features:
-10Mhz 68010
-1MB ram
-Dual UART + timer implemented as a 68c681 chip
-timer running at 1Khz, UART A for console
-interrupt driven RX support
Some amount of extending of the 68k exceptinon code was needed to
support the autovectored irqs that the 68681 uart uses. Added build
system support for 68010.
Switch to a more proper matrix. Build each of the projects in a list
with DEBUG=0 and DEBUG=2 and with two versions of the toolchain (7.5.0
and 11.2.0).
Sets things up to be easier to run things like unit tests in a later
patch.
Use the new github actions to replace the travis-ci builders which
seem to no longer work and are being removed.
This first stab is fairly rough, just matches the explicit matrix
that was in the travis-ci hooks, but at least gets back to a buildable
state again.
