microblaze: Add support for NET_MULTI api

Microblaze hasn't supported NET_MULTI support.

Signed-off-by: Michal Simek <monstr@monstr.eu>
diff --git a/board/xilinx/microblaze-generic/microblaze-generic.c b/board/xilinx/microblaze-generic/microblaze-generic.c
index 838f131..744384c 100644
--- a/board/xilinx/microblaze-generic/microblaze-generic.c
+++ b/board/xilinx/microblaze-generic/microblaze-generic.c
@@ -27,6 +27,7 @@
 
 #include <common.h>
 #include <config.h>
+#include <netdev.h>
 #include <asm/microblaze_intc.h>
 #include <asm/asm.h>
 
@@ -66,3 +67,15 @@
 	return 0;
 }
 #endif
+
+int board_eth_init(bd_t *bis)
+{
+	/*
+	 * This board either has PCI NICs or uses the CPU's TSECs
+	 * pci_eth_init() will return 0 if no NICs found, so in that case
+	 * returning -1 will force cpu_eth_init() to be called.
+	 */
+#ifdef CONFIG_XILINX_EMACLITE
+	return xilinx_emaclite_initialize(bis, XILINX_EMACLITE_BASEADDR);
+#endif
+}