Makefile: improved build flags
Makefile: use -fno-pic to compile modules
without this flag kernel can't load modules
Makefile: more build flags
Makefile: adding config variable for Os/O2/O3 compilation
fix wrong build flags setup and add more build flags
Makefile: improve build flags
Makefile: enable graphite loop optimization
Makefile: adding config variable for Ofast compilation
Makefile: cleanup and reorder build flags
Makefile: more improvement