ANDROID: pkvm: support physical port I/O access

Add a new header "io.h" to place I/O related macros and functions.
Implement two function pkvm_pio_read and pkvm_pio_write for physical
port I/O access.

Signed-off-by: Tinghao Zhang <tinghao.zhang@intel.com>

Bug: 349990461
Test: Android can run protected VMs

Change-Id: Ib154d981369a185765bb3dbd3bf7ceea1105970a
Signed-off-by: Dmytro Maluka <dmaluka@google.com>