Revert "ANDROID: x86/tdx: Rename the handle_mmio() to avoid conflict"

This reverts commit b759d217.

Reverting out-of-tree TDX patches that were originally added to
facilitate pKVM guest support for #VE. That support has been removed as
unused, thus these patches are not needed anymore.

Bug: 374338925
Test: run various VMs
Upstream-Task: 402758258

Change-Id: I598f2342ffa38f3763da6a35a9254a559f24e745
Signed-off-by: Dmytro Maluka <dmaluka@google.com>