ARM: uniphier: remove SPL support for ARMv8 SoCs

It has been a while since ARM Trusted Firmware supported UniPhier SoC
family.  U-Boot SPL was intended as a temporary loader that runs in
secure world.  It is a maintenance headache to support two different
boot mechanisms.  Secure firmware is realm of ARM Trusted Firmware
and now U-Boot only serves as a non-secure boot loader for UniPhier
ARMv8 SoCs.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/doc/README.uniphier b/doc/README.uniphier
index f79659c..e2f3b9a 100644
--- a/doc/README.uniphier
+++ b/doc/README.uniphier
@@ -55,11 +55,11 @@
     $ make CROSS_COMPILE=arm-linux-gnueabihf- DEVICE_TREE=uniphier-ld6b-ref
 
 LD11 reference board:
-    $ make uniphier_ld11_defconfig
-    $ make CROSS_COMPILE=aarch64-linux-gnu-
+    $ make uniphier_v8_defconfig
+    $ make CROSS_COMPILE=aarch64-linux-gnu- DEVICE_TREE=uniphier-ld11-ref
 
 LD20 reference board:
-    $ make uniphier_ld20_defconfig
+    $ make uniphier_v8_defconfig
     $ make CROSS_COMPILE=aarch64-linux-gnu-
 
 PXs3 reference board: