ARM: uniphier: allow to source boot script before distro-boot

Some users might need additional setups before booting the kernel.
If there is found a file 'boot.scr', run it before invoking the
distro boot command.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/configs/uniphier_ld4_sld8_defconfig b/configs/uniphier_ld4_sld8_defconfig
index bede166..98a0017 100644
--- a/configs/uniphier_ld4_sld8_defconfig
+++ b/configs/uniphier_ld4_sld8_defconfig
@@ -9,7 +9,7 @@
 CONFIG_MICRO_SUPPORT_CARD=y
 CONFIG_NR_DRAM_BANKS=3
 # CONFIG_ARCH_FIXUP_FDT_MEMORY is not set
-CONFIG_BOOTCOMMAND="run ${bootdev}boot"
+CONFIG_BOOTCOMMAND="run ${bootdev}script; run ${bootdev}boot"
 CONFIG_LOGLEVEL=6
 CONFIG_SPL_NAND_SUPPORT=y
 CONFIG_SPL_NOR_SUPPORT=y