Move the SCTP specific definition of M_NOTIFICATION onto a protocol

specific mbuf flag from sys/mbuf.h to netinet/sctp_os_bsd.h.  It is
only relevant within SCTP.

Discussed with:	tuexen

sys/netinet/sctp_os_bsd.h

@@ -428,6 +428,11 @@ typedef struct rtentry sctp_rtentry_t;
 /* This is re-pulse ourselves for sendbuf */
 #define SCTP_ZERO_COPY_SENDQ_EVENT(inp, so)
 
+/*
+ * SCTP protocol specific mbuf flags.
+ */
+#define	M_NOTIFICATION		M_PROTO5	/* SCTP notification */
+
 /*
  * IP output routines
  */

sys/sys/mbuf.h

@@ -207,8 +207,6 @@ struct mbuf {
 #define	M_FLOWID	0x00400000 /* deprecated: flowid is valid */
 #define	M_HASHTYPEBITS	0x0F000000 /* mask of bits holding flowid hash type */
 
-#define	M_NOTIFICATION	M_PROTO5    /* SCTP notification */
-
 /*
  * Flags to purge when crossing layers.
  */