Currently driver can only allocate interrupt vectors during init phase by
calling pci_alloc_irq_vectors. Change that and make use of new
pci_msix_alloc_irq_at/pci_msix_free_irq API and enable to allocate and free
more interrupts after MSIX has been enabled. Since not all platforms
supports dynamic allocation, check it with pci_msix_can_alloc_dyn.

Extend the tracker to keep track how many interrupts are allocated
initially so when all such vectors are already used, additional interrupts
are automatically allocated dynamically. Remember each interrupt allocation
method to then free appropriately. Since some features may require
interrupts allocated dynamically add appropriate VSI flag and take it into
account when allocating new interrupt.
Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)
Signed-off-by: Piotr Raczynski <piotr.raczynski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>