phy/micrel: Add support for KSZ8031

Micrel PHY KSZ8031 is similar to KSZ8021 and also requires the special
initialization of "Operation Mode Strap Override" in reg 0x16
introduced in 212ea99 (phy/micrel: Implement support for KSZ8021).

Signed-off-by: Hector Palacios <hector.palacios@digi.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/micrel_phy.h b/include/linux/micrel_phy.h
index 9dbb41a..8752dbb 100644
--- a/include/linux/micrel_phy.h
+++ b/include/linux/micrel_phy.h
@@ -19,6 +19,7 @@
 #define PHY_ID_KSZ9021		0x00221610
 #define PHY_ID_KS8737		0x00221720
 #define PHY_ID_KSZ8021		0x00221555
+#define PHY_ID_KSZ8031		0x00221556
 #define PHY_ID_KSZ8041		0x00221510
 #define PHY_ID_KSZ8051		0x00221550
 /* same id: ks8001 Rev. A/B, and ks8721 Rev 3. */