ANDROID: x86/tdx: Add ve_x86_ops to wrap different operation for virt exception

Define a ve_x86_ops to provide different handler for virt exception
related function. Later will add virt exception support for pkvm guest,
which will use this ve_x86_ops.

Bug: 395299836
Test: Boot, verify cpus are de-privileged and run a minimal protected vm.

Change-Id: Iaacae5e4c5d9a512045427d8bfb22bfad52a9422
Signed-off-by: Shaoqin Huang <shaoqin.huang@intel.com>
Reviewed-by: Jason Chen CJ <jason.cj.chen@intel.com>
Signed-off-by: Vineeth Pillai <vineethrp@google.com>