cve_check: add CVE_VERSION_SUFFIX to indicate suffix in versioning

add CVE_VERSION_SUFFIX to indicate the version suffix type, currently
works in two value, "alphabetical" if the version string uses single
alphabetical character suffix as incremental release, blank to not
consider the unidentified suffixes. This can be expand when more suffix
pattern identified.

refactor cve_check.Version class to use functools and add parameter to
handle suffix condition.

Also update testcases to cover new changes.

Signed-off-by: Lee Chee Yang <chee.yang.lee@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>