mtd: mxs_nand: fix the gf_13/14 definition issue

gf_13/14 mask was not set correctly in register definition.

Signed-off-by: Han Xu <han.xu@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
diff --git a/drivers/mtd/nand/raw/mxs_nand.c b/drivers/mtd/nand/raw/mxs_nand.c
index facedf9..1b66636 100644
--- a/drivers/mtd/nand/raw/mxs_nand.c
+++ b/drivers/mtd/nand/raw/mxs_nand.c
@@ -1474,6 +1474,8 @@
 			BCH_FLASHLAYOUT1_DATAN_SIZE_OFFSET);
 	l->eccn = (tmp & BCH_FLASHLAYOUT1_ECCN_MASK) >>
 			BCH_FLASHLAYOUT1_ECCN_OFFSET;
+	l->gf_len = (tmp & BCH_FLASHLAYOUT1_GF13_0_GF14_1_MASK) >>
+		     BCH_FLASHLAYOUT1_GF13_0_GF14_1_OFFSET;
 }
 
 /*