ralink: add 3.18 support

keep default as 3.14, mt7621 gic need to be ported to 3.18

Signed-off-by: John Crispin <blogic@openwrt.org>

SVN-Revision: 44349

target/linux/ramips/patches-3.18/0100-mtd-split-remove-padding.patch

@@ -0,0 +1,12 @@
+--- a/drivers/mtd/mtdpart.c
++++ b/drivers/mtd/mtdpart.c
+@@ -821,9 +821,6 @@ static void split_uimage(struct mtd_info
+ 		return;
+ 
+ 	len = be32_to_cpu(hdr.size) + 0x40;
+-	len = mtd_pad_erasesize(master, part->offset, len);
+-	if (len + master->erasesize > part->mtd.size)
+-		return;
+ 
+ 	if (config_enabled(CONFIG_MTD_SPLIT_UIMAGE_FW))
+ 		pr_err("Dedicated partitioner didn't split firmware partition, please fill a bug report!\n");