mtd: nand: fix multi-chip suspend problem

Symptom:
device_suspend(): mtd_cls_suspend+0x0/0x58 returns -11
PM: Device mtd14 failed to suspend: error -11
PM: Some devices failed to suspend

This patch enables other chips to be suspended if the active chip of
the controller has been suspended.
Signed-off-by: NJin Qing <b24347@freescale.com>
Signed-off-by: NLi Yang <leoli@freescale.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

drivers/mtd/nand/nand_base.c

@@ -740,8 +740,14 @@ nand_get_device(struct nand_chip *chip, struct mtd_info *mtd, int new_state)
 		return 0;
 	}
 	if (new_state == FL_PM_SUSPENDED) {
-		spin_unlock(lock);
-		return (chip->state == FL_PM_SUSPENDED) ? 0 : -EAGAIN;
+		if (chip->controller->active->state == FL_PM_SUSPENDED) {
+			chip->state = FL_PM_SUSPENDED;
+			spin_unlock(lock);
+			return 0;
+		} else {
+			spin_unlock(lock);
+			return -EAGAIN;
+		}
 	}
 	set_current_state(TASK_UNINTERRUPTIBLE);
 	add_wait_queue(wq, &wait);