1) add local_find_vcpuid_entry to find whether a cpuid leaf exist
in vcpuid cache entries.
2) find_vcpuid_entry will return the found entry if local_find_vcpuid_entry
return is not null. Otherwise, call local_find_vcpuid_entry again
when necessary.
In this case, there could eliminate recursion in find_vcpuid_entry.
Tracked-On: #861
Signed-off-by: Li, Fei1 <fei1.li@intel.com>