ANDROID: pkvm: vmx: Add the original linux vmexit handler code for comparison

Some vmexit reasons should be handled by the host, so their vmexit
handlers will just return 0. Add the original linux vmexit handler code
for comparison, which can help to understand the VMX code reusability.
Those code are disabled by using the __PKVM_HYP__.

There is no function changed.

Bug: 391539939
Test: pKVM works
Upstream-Task: 402758258

Change-Id: Ie6ac181488f6407c0d610ad70f84f280f0a4327c
Signed-off-by: Chuanxiao Dong <chuanxiao.dong@intel.com>
Signed-off-by: Dmytro Maluka <dmaluka@google.com>