arm: mvebu: fix ahci mbus config in SPL

SPL does not initialize mbus_dram_info. Don't change the ahci mbus
settings of the ROM. This allows the ahci to work in SPL.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Reviewed-by: Chris Packham <judge.packham@gmail.com>
Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/arch/arm/mach-mvebu/cpu.c b/arch/arm/mach-mvebu/cpu.c
index f09e7b1..f4b7a4f 100644
--- a/arch/arm/mach-mvebu/cpu.c
+++ b/arch/arm/mach-mvebu/cpu.c
@@ -542,6 +542,10 @@
 	const struct mbus_dram_target_info *dram;
 	int i;
 
+	/* mbus is not initialized in SPL; keep the ROM settings */
+	if (IS_ENABLED(CONFIG_SPL_BUILD))
+		return;
+
 	dram = mvebu_mbus_dram_info();
 
 	for (i = 0; i < 4; i++) {