if_ether.h: new ethernet protocol type

for High-availability Seamless Redundancy (HSR) specified in IEC 62439-3
new in linux v3.13, f421436a591d34fa5279b54a96ac07d70250cc8d

include/netinet/if_ether.h

@@ -54,6 +54,7 @@
 #define ETH_P_8021AH	0x88E7
 #define ETH_P_MVRP	0x88F5
 #define ETH_P_1588	0x88F7
+#define ETH_P_PRP	0x88FB
 #define ETH_P_FCOE	0x8906
 #define ETH_P_TDLS	0x890D
 #define ETH_P_FIP	0x8914