[NET]: linux/if_tr.h needs asm/byteorder.h

<linux/if_tr.h> uses __be16, but does not directly include
<asm/byteorder.h>.  Add this in, so that dhcp/net-tools token ring code
can compile again.
Signed-off-by: Tom Rini <trini@kernel.crashing.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/if_tr.h

@@ -19,6 +19,8 @@
 #ifndef _LINUX_IF_TR_H
 #define _LINUX_IF_TR_H
 
+#include <asm/byteorder.h>	/* For __be16 */
+
 /* IEEE 802.5 Token-Ring magic constants.  The frame sizes omit the preamble
    and FCS/CRC (frame check sequence). */
 #define TR_ALEN		6		/* Octets in one token-ring addr */