arm: mvebu: Add d-cache invalidate before enabling the d-cache

This solves some RX problems that have been seen, when using the
mvneta ethernet driver. The cache needs to be reset into a "clean"
state before using it.

Signed-off-by: Stefan Roese <sr@denx.de>
Tested-by: Kevin Smith <kevin.smith@elecsyscorp.com>
Tested-by: Dirk Eibach <dirk.eibach@gdsys.cc>

arch/arm/mach-mvebu/cpu.c

@@ -240,6 +240,9 @@ int cpu_eth_init(bd_t *bis)
 #ifndef CONFIG_SYS_DCACHE_OFF
 void enable_caches(void)
 {
+	/* Avoid problem with e.g. neta ethernet driver */
+	invalidate_dcache_all();
+
 	/* Enable D-cache. I-cache is already enabled in start.S */
 	dcache_enable();
 }