Move sys/display.h functions into their own directory.

libc/Makefile

@@ -173,7 +173,6 @@ $(CPUDIR)/signal.o \
 $(CPUDIR)/syscall.o \
 dirent/fddir-sortix.o \
 dirent/scandir.o \
-dispmsg_issue.o \
 dlfcn.o \
 errorprint.o \
 fcloseall.o \
@@ -259,6 +258,7 @@ stdlib/on_exit.o \
 stdlib/rand.o \
 stdlib/realpath.o \
 stdlib/system.o \
+sys/display/dispmsg_issue.o \
 sys/socket/accept4.o \
 sys/socket/accept.o \
 sys/socket/bind.o \

libc/sys/display/dispmsg_issue.cpp

@@ -17,7 +17,7 @@
     You should have received a copy of the GNU Lesser General Public License
     along with the Sortix C Library. If not, see <http://www.gnu.org/licenses/>.
 
-    dispmsg_issue.cpp
+    sys/display/dispmsg_issue.cpp
     Send a message to the display engine.
 
 *******************************************************************************/