vmm, devices: Remove hardcoded IRQ number for GED device

Remove the previously hardcoded IRQ number used for the GED device.
Instead allocate the IRQ using the allocator and use that value in the
definition in the ACPI device.

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

devices/src/acpi.rs

@@ -57,13 +57,15 @@ impl BusDevice for AcpiShutdownDevice {
 pub struct AcpiGEDDevice {
     interrupt: Box<dyn Interrupt>,
     notification_type: HotPlugNotificationType,
+    ged_irq: u32,
 }
 
 impl AcpiGEDDevice {
-    pub fn new(interrupt: Box<dyn Interrupt>) -> AcpiGEDDevice {
+    pub fn new(interrupt: Box<dyn Interrupt>, ged_irq: u32) -> AcpiGEDDevice {
         AcpiGEDDevice {
             interrupt,
             notification_type: HotPlugNotificationType::NoDevicesChanged,
+            ged_irq,
         }
     }
 
@@ -74,6 +76,10 @@ impl AcpiGEDDevice {
         self.notification_type = notification_type;
         self.interrupt.deliver()
     }
+
+    pub fn irq(&self) -> u32 {
+        self.ged_irq
+    }
 }
 
 // I/O port reports what type of notification was made