pvmfw: Use vmbase::logger and the log API

For now, initialize the logger to print any log entry.

Replace all println!() with their appropriate corresponding log macro.

Rework the main() bootflow to have a single reboot() point.

Test: -
Change-Id: I3633b7f4c406887c6a810c43f2ec5a6ccf4b7907
diff --git a/pvmfw/Android.bp b/pvmfw/Android.bp
index 84cb18c..296644a 100644
--- a/pvmfw/Android.bp
+++ b/pvmfw/Android.bp
@@ -9,6 +9,7 @@
     srcs: ["src/main.rs"],
     edition: "2021",
     rustlibs: [
+        "liblog_rust_nostd",
         "libvmbase",
     ],
     apex_available: ["com.android.virt"],