Multiple device IRQ support

[Deniz-Eren]

Currently the implementation in src/include/interrupt.h and src/interrupt.c only supports a single IRQ being allocated to the devices. If multiple IRQs are indicated by the OS the driver will exit with an error. In practice this scenario has not occured in emulation or during real hardware testing, however this needs to be made more general.

Error handler in src/pci.c must be removed when implementation made:

log_err("read multiple (%d) IRQs\n", nirq);

[Deniz-Eren]

Muliple IRQ support is now required as a result of MSI and MSI-X supported devices, see #7 and #19

[Deniz-Eren]

Multiple IRQ support has been implemented and rebased to pull request #8.

Merging to main will be tracked in #7