kvm tools: Introduce IRQ registry

kvm tools: Introduce IRQ registry

Instead of having static definitions of devices, Use a
dynamic registry of pci devices.

The structure is a rbtree which holds device types (net,
blk, etc). Each device entry holds a list of IRQ lines
associated with that device (pin).

Devices dynamically register upon initialization, and receive
a set of: device id, irq pin and irq line.

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>