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>

arch/um/drivers/line.c

@@ -5,6 +5,7 @@
 
 #include "linux/irqreturn.h"
 #include "linux/kd.h"
+#include "linux/sched.h"
 #include "chan_kern.h"
 #include "irq_kern.h"
 #include "irq_user.h"

arch/um/drivers/port_kern.c

@@ -7,6 +7,7 @@
 #include "linux/interrupt.h"
 #include "linux/list.h"
 #include "linux/mutex.h"
+#include "linux/workqueue.h"
 #include "asm/atomic.h"
 #include "init.h"
 #include "irq_kern.h"

arch/um/kernel/irq.c

@@ -10,6 +10,7 @@
 #include "linux/interrupt.h"
 #include "linux/kernel_stat.h"
 #include "linux/module.h"
+#include "linux/sched.h"
 #include "linux/seq_file.h"
 #include "as-layout.h"
 #include "kern_util.h"