sha1: Update architecture detection for unified x86 architecture
sha1: Update architecture detection for unified x86 architecture

- Update architecture detection in sha1 Kbuild Makefile to work with
unified x86 architecture as well as i386/x86_64

cmusatyalab/openisr,cmusatyalab/openisr,cmusatyalab/openisr,cmusatyalab/openisr,cmusatyalab/openisr