spusched: fix mismerge in spufs.h

spufs.h now has two enums for the sched_flags leading to identical
values for SPU_SCHED_WAS_ACTIVE and SPU_SCHED_NOTIFY_ACTIVE.  Merge
them into a single enum as they were in the IBM development tree.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>