Don't declare our own common version of the library variable `ospeed'

without even getting its type correct.  Include <termcap.h> to get its
declaration.  Our initialization of it is still dubious, but it agrees
with ncurses' documentation of it (none) and with ncurses' recently
fixed internals for it (old speeds from <sys/ttydev.h>) and with the
4.4Lite documentation for it.

games/backgammon/backgammon/main.c

@@ -46,6 +46,7 @@ static const char rcsid[] =
 #endif /* not lint */
 
 #include <stdio.h>
+#include <termcap.h>
 #include <unistd.h>
 #include <string.h>
 #include <stdlib.h>
@@ -57,7 +58,6 @@ static const char rcsid[] =
 
 extern const char	*const instr[];		/* text of instructions */
 extern const char	*const message[];	/* update message */
-char	ospeed;					/* tty output speed */
 
 const char	*helpm[] = {			/* help message */
 	"Enter a space or newline to roll, or",