Update hw for benchmarking and api changes

The hw platform is maintained in order to run benchmark comparisons with
the seL4 platform. As we develop the seL4 platform we change some of
the library apis. This commit adds:
- Extra interrupt numbers to the PIC
- A serial input interrupt handler for saving, resetting and printing
the tsc for measuring idle time
- Changes default console output to use COM port instead of VGA
- Changes for changed library functions
- A rumprun-bake configuration for only using ethernet modules

Translate LF to CRLF in serialcons.c

Serial console support for hw (x86) platform

Implement basic serial console (output-only, without interrupts) for
hw/x86. Console output defaults to VGA, serial console is only used when
the BIOS claims VGA is not present and a serial port is present.