Revert "mvebu: remove linux 4.4 support"

This reverts commit 51397d7d95.
There are some unresolved random crashes on WRT1900AC v1 that still need
to be sorted out

Signed-off-by: Felix Fietkau <nbd@nbd.name>

target/linux/mvebu/patches-4.4/103-remove-nand-driver-bug.patch

@@ -0,0 +1,13 @@
+Remove a BUG() call that would crash on a race condition that should
+otherwise be harmless.
+
+--- a/drivers/mtd/nand/pxa3xx_nand.c
++++ b/drivers/mtd/nand/pxa3xx_nand.c
+@@ -701,7 +701,6 @@ static void handle_data_pio(struct pxa3x
+ 	default:
+ 		dev_err(&info->pdev->dev, "%s: invalid state %d\n", __func__,
+ 				info->state);
+-		BUG();
+ 	}
+ 
+ 	/* Update buffer pointers for multi-page read/write */