vm-device, pci, devices: Remove InterruptSourceGroup::{un}mask

The calls to these functions are always preceded by a call to
InterruptSourceGroup::update(). By adding a masked boolean to that
function call it possible to remove 50% of the calls to the
KVM_SET_GSI_ROUTING ioctl as the the update will correctly handle the
masked or unmasked case.

This causes the ioctl to disappear from the perf report for a boot of
the VM.

Signed-off-by: Rob Bradford <robert.bradford@intel.com>

devices/src/gic.rs

@@ -76,6 +76,7 @@ impl InterruptController for Gic {
                 .update(
                     i as InterruptIndex,
                     InterruptSourceConfig::LegacyIrq(config),
+                    false,
                 )
                 .map_err(Error::EnableInterrupt)?;
         }