Move common VM functionality into a library.

Bug: 223166344
Test: Ran unprotected VM under crosvm.
Change-Id: I3b027c3a5de037c2adc75cf816518d8db5e10587
diff --git a/pvmfw/src/exceptions.rs b/pvmfw/src/exceptions.rs
index f67a524..61f7846 100644
--- a/pvmfw/src/exceptions.rs
+++ b/pvmfw/src/exceptions.rs
@@ -14,61 +14,59 @@
 
 //! Exception handlers.
 
-use crate::console::emergency_write_str;
-use crate::eprintln;
 use core::arch::asm;
-use psci::system_reset;
+use vmbase::{console::emergency_write_str, eprintln, power::reboot};
 
 #[no_mangle]
 extern "C" fn sync_exception_current() {
     emergency_write_str("sync_exception_current\n");
     print_esr();
-    system_reset().unwrap();
+    reboot();
 }
 
 #[no_mangle]
 extern "C" fn irq_current() {
     emergency_write_str("irq_current\n");
-    system_reset().unwrap();
+    reboot();
 }
 
 #[no_mangle]
 extern "C" fn fiq_current() {
     emergency_write_str("fiq_current\n");
-    system_reset().unwrap();
+    reboot();
 }
 
 #[no_mangle]
 extern "C" fn serr_current() {
     emergency_write_str("serr_current\n");
     print_esr();
-    system_reset().unwrap();
+    reboot();
 }
 
 #[no_mangle]
 extern "C" fn sync_lower() {
     emergency_write_str("sync_lower\n");
     print_esr();
-    system_reset().unwrap();
+    reboot();
 }
 
 #[no_mangle]
 extern "C" fn irq_lower() {
     emergency_write_str("irq_lower\n");
-    system_reset().unwrap();
+    reboot();
 }
 
 #[no_mangle]
 extern "C" fn fiq_lower() {
     emergency_write_str("fiq_lower\n");
-    system_reset().unwrap();
+    reboot();
 }
 
 #[no_mangle]
 extern "C" fn serr_lower() {
     emergency_write_str("serr_lower\n");
     print_esr();
-    system_reset().unwrap();
+    reboot();
 }
 
 #[inline]