ath25: update kernel from 3.18 to 4.4

Summary of changes:
	* moved config-3.18 to config-4.4 and patches-3.18 to patches-4.4
	* removed most of the first two patches, that seem to be upstream already
	* changed deprecated/removed IRQF_DISABLED to zero following examples in upstream kernel patches
	* added config line to disable device-tree to satisfy kernel configuration
	* add new image generation code

Build tested and run tested on an Accton MR3201A.

Signed-off-by: Russell Senior <russell@personaltelco.net>
Signed-off-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Signed-off-by: John Crispin <john@phrozen.org>

target/linux/ath25/patches-4.4/141-redboot_partition_scan.patch

@@ -0,0 +1,44 @@
+--- a/drivers/mtd/redboot.c
++++ b/drivers/mtd/redboot.c
+@@ -79,12 +79,18 @@ static int parse_redboot_partitions(stru
+ 	static char nullstring[] = "unallocated";
+ #endif
+ 
++	buf = vmalloc(master->erasesize);
++	if (!buf)
++		return -ENOMEM;
++
++ restart:
+ 	if ( directory < 0 ) {
+ 		offset = master->size + directory * master->erasesize;
+ 		while (mtd_block_isbad(master, offset)) {
+ 			if (!offset) {
+ 			nogood:
+ 				printk(KERN_NOTICE "Failed to find a non-bad block to check for RedBoot partition table\n");
++				vfree(buf);
+ 				return -EIO;
+ 			}
+ 			offset -= master->erasesize;
+@@ -97,10 +103,6 @@ static int parse_redboot_partitions(stru
+ 				goto nogood;
+ 		}
+ 	}
+-	buf = vmalloc(master->erasesize);
+-
+-	if (!buf)
+-		return -ENOMEM;
+ 
+ 	printk(KERN_NOTICE "Searching for RedBoot partition table in %s at offset 0x%lx\n",
+ 	       master->name, offset);
+@@ -173,6 +175,11 @@ static int parse_redboot_partitions(stru
+ 	}
+ 	if (i == numslots) {
+ 		/* Didn't find it */
++		if (offset + master->erasesize < master->size) {
++			/* not at the end of the flash yet, maybe next block */
++			directory++;
++			goto restart;
++		}
+ 		printk(KERN_NOTICE "No RedBoot partition table detected in %s\n",
+ 		       master->name);
+ 		ret = 0;