Move common VM functionality into a library.

Bug: 223166344
Test: Ran unprotected VM under crosvm.
Change-Id: I3b027c3a5de037c2adc75cf816518d8db5e10587
diff --git a/pvmfw/Android.bp b/pvmfw/Android.bp
index 3d77b2c..7385288 100644
--- a/pvmfw/Android.bp
+++ b/pvmfw/Android.bp
@@ -13,8 +13,7 @@
         "libcore.rust_sysroot",
     ],
     rustlibs: [
-        "libpsci",
-        "libspin_nostd",
+        "libvmbase",
     ],
     enabled: false,
     target: {