headers: remove sched.h from interrupt.h

After m68k's task_thread_info() doesn't refer to current,
it's possible to remove sched.h from interrupt.h and not break m68k!
Many thanks to Heiko Carstens for allowing this.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>

net/irda/irnet/irnet_irda.c

@@ -9,6 +9,7 @@
  */
 
 #include "irnet_irda.h"		/* Private header */
+#include <linux/sched.h>
 #include <linux/seq_file.h>
 #include <asm/unaligned.h>
 

net/irda/irnet/irnet_ppp.c

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