net/macb: ethtool interface: add register dump feature

Add macb_get_regs() ethtool function and its helper function:
macb_get_regs_len().
The version field is deduced from the IP revision which gives the
"MACB or GEM" information. An additional version field is reserved.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Reviewed-by: Ben Hutchings <bhutchings@solarflare.com>
Tested-by: Joachim Eastwood <manabian@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h
index 024a270..232dca6 100644
--- a/drivers/net/ethernet/cadence/macb.h
+++ b/drivers/net/ethernet/cadence/macb.h
@@ -10,6 +10,9 @@
 #ifndef _MACB_H
 #define _MACB_H
 
+#define MACB_GREGS_NBR 16
+#define MACB_GREGS_VERSION 1
+
 /* MACB register offsets */
 #define MACB_NCR				0x0000
 #define MACB_NCFGR				0x0004