ARM: uniphier: merge two defconfig files

PH1-Pro5 support and ProXstream2/PH1-LD6b support can coexist in one
image and there is bit more room in SPL to accommodate all of them.
Merge uniphier_pro5_defconfig into uniphier_pxs2_defconfig.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/doc/README.uniphier b/doc/README.uniphier
index 5ac52bd..6c3b092 100644
--- a/doc/README.uniphier
+++ b/doc/README.uniphier
@@ -45,8 +45,8 @@
     $ make CROSS_COMPILE=arm-linux-gnueabi-
 
 PH1-Pro5 4KBOX Board:
-    $ make uniphier_pro5_defconfig
-    $ make CROSS_COMPILE=arm-linux-gnueabi-
+    $ make uniphier_pxs2_ld6b_defconfig
+    $ make CROSS_COMPILE=arm-linux-gnueabi- DEVICE_TREE=uniphier-ph1-pro5-4kbox
 
 ProXstream2 Gentil board:
     $ make uniphier_pxs2_ld6b_defconfig