[MAKEFILE] Avoid quoting the "VMM_MODNAME" macro variable on the command line.

Since the "VMM_MODNAME" macro variable will be used for defining "modtbl" and
"nidtbl", it must not contain double quotes.
[CORE] Avoid declaring "nidtbl" and "modtbl" structures as unused and static.

As being declared as static and unused, the "nidtbl" and "modtbl" structures
are removed from the objects compiled in -O1 or more optimized level, leading
to empty ".nidtbl" and ".modtbl" sections.
The module tree tables are now named with "__modtbl__" and the module name
(the compiled file name) to avoid multiple definitions.
[CORE] Allow a different IRQ chip for extended IRQ mapping.

Some drivers will need a different IRQ chip to manage the extended IRQS. For
example, GPIO drivers, as the i.MX one, may define PIN specific extended IRQs.
[DRIVERS] Many corrections on the i.MX GPIO driver.

- Setting IRQ type retrived the wrong GPIO PIN number.
- The extended IRQ handling was not correctly done, calling the IRQ handler
instead of the associated IRQ actions.
- The HW IRQ chip was set on the GPIO IRQ one, leading to an IRQ never set as
processed to the GIC controller.
- The IRQ generic chip is now set for the extended IRQ, and the GIC chip is
left for the HW one.
- The extended IRQ now mask, unmask, and ack the GPIO controller IRQ, through
the GPIO IRQ chip.
[DRIVERS] Inverting the IRQ type set and registering calls.
[ARM] Correcting i.MX clock controller interrupt numbers.
[DRIVERS] Improving i.MX GPIO driver.
[CORE] Extended IRQs improvments for xvisor-next done.

- The extended IRQs are now always enabled.
- Macros and structures have been renamed to all have a "host_extirq" part in
  common.
- The "vmm_host_extirqs" structure have been renamed "vmm_host_extirq_group".
- A bitmap is used for extended IRQ allocation.
- Error management have been improved.
- A rework to allow using Linux "irq_domain" have been done, but you have to
  use "vmm_host_extirq_to_hwirq" to convert an global IRQ to the domain IRQ.

Moreover, group allocation is dynamic, using a "dlist".

There is still a CONFIG_HOST_EXTIRQ_COUNT menuconfig variable.