[vmbase] Move SwiotlbInfo from pvmfw to vmbase

for reuse in both pvmfw and rialto to init shared memory.

Bug: 284462758
Test: m pvmfw_img
Change-Id: Ibe7b8b1bb8d10fbbdc4ec3348e801084c9a93bfd
diff --git a/pvmfw/src/dice.rs b/pvmfw/src/dice.rs
index 3116456..fbab013 100644
--- a/pvmfw/src/dice.rs
+++ b/pvmfw/src/dice.rs
@@ -14,17 +14,16 @@
 
 //! Support for DICE derivation and BCC generation.
 
-use crate::cstr;
 use core::ffi::c_void;
 use core::mem::size_of;
 use core::slice;
-use vmbase::memory::flushed_zeroize;
-
 use diced_open_dice::{
     bcc_format_config_descriptor, bcc_handover_main_flow, hash, Config, DiceMode, Hash,
     InputValues, HIDDEN_SIZE,
 };
 use pvmfw_avb::{DebugLevel, Digest, VerifiedBootData};
+use vmbase::cstr;
+use vmbase::memory::flushed_zeroize;
 
 fn to_dice_mode(debug_level: DebugLevel) -> DiceMode {
     match debug_level {