ARM: imx6: dh-imx6: Use sf update instead of sf erase and write

With sf update fixed to support unaligned start offset, use plain
sf update to update the bootloader in SPI NOR. This also helps
avoid the case where not enough SPI NOR has been erased and the
bootloader has been written to unerased area, and thus corrupted.

Signed-off-by: Marek Vasut <marex@denx.de>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
diff --git a/include/configs/dh_imx6.h b/include/configs/dh_imx6.h
index 0f7e1c5..2040deb 100644
--- a/include/configs/dh_imx6.h
+++ b/include/configs/dh_imx6.h
@@ -60,8 +60,7 @@
 	"fdtfile=imx6q-dhcom-pdk2.dtb\0"\
 	"update_sf=" /* Erase SPI NOR and install U-Boot from SD */	\
 		"load mmc 0:1 ${loadaddr} /boot/u-boot-with-spl.imx && "\
-		"sf probe && sf erase 0x0 0x100000 && "			\
-		"sf write ${loadaddr} 0x400 ${filesize}\0"		\
+		"sf probe && sf update ${loadaddr} 0x400 ${filesize}\0"	\
 	BOOTENV
 
 #define BOOT_TARGET_DEVICES(func) \