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>
diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
index a9d7070..e941367 100644
--- a/drivers/uio/uio.c
+++ b/drivers/uio/uio.c
@@ -19,6 +19,7 @@
 #include <linux/device.h>
 #include <linux/mm.h>
 #include <linux/idr.h>
+#include <linux/sched.h>
 #include <linux/string.h>
 #include <linux/kobject.h>
 #include <linux/uio_driver.h>