drivers: remove extraneous includes of smp_lock.h

These were missed the last time I cleaned this up
globally, because of code moving around or new code
getting merged.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

drivers/tty/n_r3964.c

@@ -57,7 +57,6 @@
 #include <linux/ioport.h>
 #include <linux/in.h>
 #include <linux/slab.h>
-#include <linux/smp_lock.h>
 #include <linux/tty.h>
 #include <linux/errno.h>
 #include <linux/string.h>	/* used in new tty drivers */