Fix virtual_terminal.cpp build on FreeBSD

- need to shuffle some Linux includes behind an ifdef, and some
  FreeBSD ones as well
- FreeBSD has no notion of major device numbers anymore, so the
  isTty() function can't really tell. Just ignore the check --
  I'm assuming the somewhat-standard isatty() doesn't do what
  is wanted, since otherwise it would be used.

virtual_terminal.cpp

@@ -26,16 +26,21 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <QDebug>
 #include <QSocketNotifier>
 // linux
+#ifdef Q_OS_LINUX
 #include <linux/major.h>
 #include <linux/kd.h>
 #include <linux/vt.h>
+#include <sys/sysmacros.h>
+#endif
+#ifdef Q_OS_FREEBSD
+#include <sys/consio.h>
+#endif
 // system
 #include <fcntl.h>
 #include <unistd.h>
 #include <sys/ioctl.h>
 #include <sys/signalfd.h>
 #include <sys/stat.h>
-#include <sys/sysmacros.h>
 // c++
 #include <csignal>
 
@@ -81,9 +86,14 @@ static bool isTty(int fd)
     if (fstat(fd, &st) == -1) {
         return false;
     }
+#ifdef Q_OS_LINUX
+    // Not a TTY device or weird vt number, skip it
     if (major(st.st_rdev) != TTY_MAJOR || minor (st.st_rdev) <= 0 || minor(st.st_rdev) >= 64) {
         return false;
     }
+#endif
+    // FreeBSD doesn't have a notion of major device number, so nothing
+    //   to check. isatty() might not do the trick.
     return true;
 }