[libc] Remove fileno from GPU entrypoints

Author: jhuber6

libc/config/gpu/entrypoints.txt

@@ -179,7 +179,6 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.stdio.ferror
     libc.src.stdio.fseek
     libc.src.stdio.fflush
-    libc.src.stdio.fileno
     libc.src.stdio.ftell
     libc.src.stdio.clearerr
     libc.src.stdio.puts