arm: mvebu: Add Serdes PHY config code

This code is ported from the Marvell bin_hdr code into mainline
SPL U-Boot. It needs to be executed very early so that the devices
connected to the serdes PHY are configured correctly.

Signed-off-by: Stefan Roese <sr@denx.de>
Reviewed-by: Luka Perkov <luka.perkov@sartura.hr>
diff --git a/arch/arm/mvebu-common/Makefile b/arch/arm/mvebu-common/Makefile
index 9dcab69..de243fea 100644
--- a/arch/arm/mvebu-common/Makefile
+++ b/arch/arm/mvebu-common/Makefile
@@ -10,3 +10,5 @@
 obj-y	+= gpio.o
 obj-$(CONFIG_ARMADA_XP) += mbus.o
 obj-y	+= timer.o
+
+obj-y	+= serdes/