net: phy: broadcom: add support for BCM54210E

It's Broadcom PHY simply described as single-port
RGMII 10/100/1000BASE-T PHY. It requires disabling delay skew and GTXCLK
bits.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/brcmphy.h b/include/linux/brcmphy.h
index cf93f13..5881d1f 100644
--- a/include/linux/brcmphy.h
+++ b/include/linux/brcmphy.h
@@ -17,6 +17,7 @@
 #define PHY_ID_BCM5482			0x0143bcb0
 #define PHY_ID_BCM5411			0x00206070
 #define PHY_ID_BCM5421			0x002060e0
+#define PHY_ID_BCM54210E		0x600d84a0
 #define PHY_ID_BCM5464			0x002060b0
 #define PHY_ID_BCM5461			0x002060c0
 #define PHY_ID_BCM54612E		0x03625e60