ANDROID: pkvm: x86: Add support of cpuid for protected VM in pkvm

Protected VM can use cpuid to detect if it is running on pkvm
hypervisor, so add support for emulating cpuid for protected VM in pkvm.

PKVM reuse the cpuid for detecting KVM, thus pkvm can intercept the
hypervisor detection once PKVM has been enabled.

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

Change-Id: I7cab988b3e6a578e851eb49e45c072a857fb900b
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>