headers: smp_lock.h redux

* Remove smp_lock.h from files which don't need it (including some headers!)
* Add smp_lock.h to files which do need it
* Make smp_lock.h include conditional in hardirq.h
  It's needed only for one kernel_locked() usage which is under CONFIG_PREEMPT

  This will make hardirq.h inclusion cheaper for every PREEMPT=n config
  (which includes allmodconfig/allyesconfig, BTW)

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

net/irda/af_irda.c

@@ -45,6 +45,7 @@
 #include <linux/capability.h>
 #include <linux/module.h>
 #include <linux/types.h>
+#include <linux/smp_lock.h>
 #include <linux/socket.h>
 #include <linux/sockios.h>
 #include <linux/init.h>

net/irda/irnet/irnet.h

@@ -241,7 +241,6 @@
 #include <linux/module.h>
 
 #include <linux/kernel.h>
-#include <linux/smp_lock.h>
 #include <linux/skbuff.h>
 #include <linux/tty.h>
 #include <linux/proc_fs.h>

net/irda/irnet/irnet_ppp.c

@@ -13,6 +13,7 @@
  *	2) as a control channel (write commands, read events)
  */
 
+#include <linux/smp_lock.h>
 #include "irnet_ppp.h"		/* Private header */
 /* Please put other headers in irnet.h - Thanks */