ARM: uniphier: rename second stage loader name

For the memory footprint reason, the Boot ROM can not load the ARM
Trusted Firmware BL1 directly when Trusted Board Boot is enabled.
The second stage loader is Socionext's own firmware, so rename it
for clarification.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/include/configs/uniphier.h b/include/configs/uniphier.h
index ab35191..2976d63 100644
--- a/include/configs/uniphier.h
+++ b/include/configs/uniphier.h
@@ -142,7 +142,7 @@
 #if defined(CONFIG_ARM64) && !defined(CONFIG_ARMV8_MULTIENTRY)
 /* ARM Trusted Firmware */
 #define BOOT_IMAGES \
-	"second_image=bl1.bin\0" \
+	"second_image=unph_bl.bin\0" \
 	"third_image=fip.bin\0"
 #else
 #define BOOT_IMAGES \