devices: pvpanic: add method for DeviceManager

Add method for DeviceManager to invoke.

Signed-off-by: Yi Wang <foxywang@tencent.com>
Signed-off-by: Rob Bradford <rbradford@rivosinc.com>

devices/src/pvpanic.rs

@@ -136,6 +136,10 @@ impl PvPanicDevice {
             events: self.events,
         }
     }
+
+    pub fn config_bar_addr(&self) -> u64 {
+        self.configuration.get_bar_addr(0)
+    }
 }
 
 impl BusDevice for PvPanicDevice {