Ticket #3267: mc fails to build against musl libc.

mc fails to build when using musl as the libc provider. This is due to
the CTRL() macro not being defined in <termios.h>. We could include
<sys/ttydefaults.h> explicitly but it's easier just to ensure CTRL is
defined.

This patch taken from the Sabotage Linux distro which fixes this. This
patch has also been tested and works with the OpenEmbedded build
system.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
Merge branch '3267_musl_libc'

* 3267_musl_libc:
  Ticket #3267: mc fails to build against musl libc.