arm: mvebu: gdsys: Remove custom spl_board_init()

The gdsys a38x config file (controlcenterdc_defconfig) uses BootROM to
load U-Boot proper.

Since it is now possible to do this via U-Boot SPL framework, we do not
need to provide custom spl_board_init() which calls return_to_bootrom().

Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Chris Packham <judge.packham@gmail.com>
Reviewed-by: Stefan Roese <sr@denx.de>
diff --git a/board/gdsys/a38x/Makefile b/board/gdsys/a38x/Makefile
index 32fffab..4b13859 100644
--- a/board/gdsys/a38x/Makefile
+++ b/board/gdsys/a38x/Makefile
@@ -4,7 +4,7 @@
 # Copyright (C) 2015 Reinhard Pfau <reinhard.pfau@gdsys.cc>
 # Copyright (C) 2016 Mario Six <mario.six@gdsys.cc>
 
-obj-$(CONFIG_TARGET_CONTROLCENTERDC) += controlcenterdc.o hre.o spl.o keyprogram.o dt_helpers.o
+obj-$(CONFIG_TARGET_CONTROLCENTERDC) += controlcenterdc.o hre.o keyprogram.o dt_helpers.o
 
 ifeq ($(CONFIG_SPL_BUILD),)
 obj-$(CONFIG_TARGET_CONTROLCENTERDC) += hydra.o ihs_phys.o