arm-bsp-extras/scp-firmware/fvp-rd-aspen: Integrate FMU module

The FMU (Fault management unit) collects and collates faults from
different components. The module installs interrupt handlers to turn
fault interrupts into notifications and exposes an API to control how
faults are reported.

These patches introduce the module and integration tests using a new
integration test module. There are also patches to fix minor issues with
the AArch64 port and the debugger component.

Signed-off-by: Peter Hoyes <peter.hoyes@arm.com>