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/arch/blackfin/kernel/time.c b/arch/blackfin/kernel/time.c
index e5069fe..bd3b53d 100644
--- a/arch/blackfin/kernel/time.c
+++ b/arch/blackfin/kernel/time.c
@@ -14,6 +14,7 @@
 #include <linux/time.h>
 #include <linux/irq.h>
 #include <linux/delay.h>
+#include <linux/sched.h>
 
 #include <asm/blackfin.h>
 #include <asm/time.h>