cmake ALLEGRO_HAVE_SYS_UTSNAME_H examples

liballeg/allegro5 CMakeLists.txt :512

check_include_files(sys/utsname.h ALLEGRO_HAVE_SYS_UTSNAME_H)

adventuregamestudio/ags libsrc/allegro/CMakeLists.txt :45

check_include_files(sys/utsname.h ALLEGRO_HAVE_SYS_UTSNAME_H)