hikey: migrate to bl2_el3

Since non-TF ROM is used in HiKey platform (Hisilicon Hi6220 SoC),
replace BL1 by BL2_EL3 in normal boot mode.

When we recovery images in recovery mode, keep to use BL1.

Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
diff --git a/docs/plat/hikey.rst b/docs/plat/hikey.rst
index 99259f3..33e6514 100644
--- a/docs/plat/hikey.rst
+++ b/docs/plat/hikey.rst
@@ -91,6 +91,7 @@
 
        cd ${BUILD_PATH}/l-loader
        ln -sf ${EDK2_OUTPUT_DIR}/FV/bl1.bin
+       ln -sf ${EDK2_OUTPUT_DIR}/FV/bl2.bin
        ln -sf ${BUILD_PATH}/atf-fastboot/build/hikey/${FASTBOOT_BUILD_OPTION}/bl1.bin fastboot.bin
        make hikey PTABLE_LST=aosp-8g
 
@@ -142,17 +143,18 @@
 
        $sudo apt-get purge modemmanager
 
--  Run the command to download l-loader.bin into HiKey.
+-  Run the command to download recovery.bin into HiKey.
 
    .. code:: shell
 
-       $sudo python hisi-idt.py -d /dev/ttyUSB1 --img1 l-loader.bin
+       $sudo python hisi-idt.py -d /dev/ttyUSB1 --img1 recovery.bin
 
 -  Update images. All aosp or debian images could be fetched from `link <https://builds.96boards.org/>`__.
 
    .. code:: shell
 
        $sudo fastboot flash ptable prm_ptable.img
+       $sudo fastboot flash loader l-loader.bin
        $sudo fastboot flash fastboot fip.bin
        $sudo fastboot flash boot boot.img
        $sudo fastboot flash cache cache.img