[pvmfw] Extract a library to support various hypervisor backends

This cl extracts a library libhyp from pvmfw to support
various hypervisor backends including kvm.

Bug: 272226230
Test: m pvmfw_img
Change-Id: I5307cb5d6cccc7a01af6bc9c46ae7111c0d51e93
diff --git a/pvmfw/src/entry.rs b/pvmfw/src/entry.rs
index 00f0e9b..e0af856 100644
--- a/pvmfw/src/entry.rs
+++ b/pvmfw/src/entry.rs
@@ -20,12 +20,12 @@
 use crate::heap;
 use crate::helpers;
 use crate::memory::MemoryTracker;
-use crate::mmio_guard;
 use crate::mmu;
 use crate::rand;
 use core::arch::asm;
 use core::num::NonZeroUsize;
 use core::slice;
+use hyp::mmio_guard;
 use log::debug;
 use log::error;
 use log::info;