Revert "ANDROID: x86/tdx: Move virt exception handler code to virt_exception.c"

This reverts commit dd43a9a7.

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: I9ed38363556fe5c4eb46f4aeb66d3a81dd7e0271
Signed-off-by: Dmytro Maluka <dmaluka@google.com>