mtd: Missing slab.h include

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
index 0f9fc5e..c41d278 100644
--- a/drivers/mtd/nand/denali.c
+++ b/drivers/mtd/nand/denali.c
@@ -21,6 +21,7 @@
 #include <linux/delay.h>
 #include <linux/wait.h>
 #include <linux/mutex.h>
+#include <linux/slab.h>
 #include <linux/pci.h>
 #include <linux/mtd/mtd.h>
 #include <linux/module.h>