mxs_nand: Add support for i.MX8M

Update the gpmi/apbh_dma/bch drivers and relevant registers for i.MX8M.

Signed-off-by: Ye Li <ye.li@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
diff --git a/drivers/mtd/nand/raw/Kconfig b/drivers/mtd/nand/raw/Kconfig
index 23201ca..c46fec3 100644
--- a/drivers/mtd/nand/raw/Kconfig
+++ b/drivers/mtd/nand/raw/Kconfig
@@ -259,12 +259,12 @@
 
 config NAND_MXS
 	bool "MXS NAND support"
-	depends on MX23 || MX28 || MX6 || MX7
+	depends on MX23 || MX28 || MX6 || MX7 || IMX8M
 	select SYS_NAND_SELF_INIT
 	imply CMD_NAND
 	select APBH_DMA
-	select APBH_DMA_BURST if ARCH_MX6 || ARCH_MX7
-	select APBH_DMA_BURST8 if ARCH_MX6 || ARCH_MX7
+	select APBH_DMA_BURST if ARCH_MX6 || ARCH_MX7 || ARCH_IMX8M
+	select APBH_DMA_BURST8 if ARCH_MX6 || ARCH_MX7 || ARCH_IMX8M
 	help
 	  This enables NAND driver for the NAND flash controller on the
 	  MXS processors.