highbank: add custom ahci_link_up function

The Calxeda highbank SOC needs a custom sequence to bring up SATA links,
so override ahci_link_up with custom function to handle combophy setup.

Signed-off-by: Mark Langsdorf <mark.langsdorf@gmail.com>
Signed-off-by: Richard Gibbs
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Andre Przywara <osp@andrep.de>
diff --git a/board/highbank/Makefile b/board/highbank/Makefile
index d3eb232..ce7ee68 100644
--- a/board/highbank/Makefile
+++ b/board/highbank/Makefile
@@ -5,4 +5,4 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
-obj-y	:= highbank.o
+obj-y	:= highbank.o ahci.o