Update to v4.15 kernel headers.

Test: Compiles, boots bullhead/hikey960.
Change-Id: I118beb8b6cac0881b1270f9bf6981959297a41a8
diff --git a/libc/kernel/uapi/linux/sctp.h b/libc/kernel/uapi/linux/sctp.h
index 9a55459..cc714ff 100644
--- a/libc/kernel/uapi/linux/sctp.h
+++ b/libc/kernel/uapi/linux/sctp.h
@@ -77,6 +77,8 @@
 #define SCTP_RESET_ASSOC 120
 #define SCTP_ADD_STREAMS 121
 #define SCTP_SOCKOPT_PEELOFF_FLAGS 122
+#define SCTP_STREAM_SCHEDULER 123
+#define SCTP_STREAM_SCHEDULER_VALUE 124
 #define SCTP_PR_SCTP_NONE 0x0000
 #define SCTP_PR_SCTP_TTL 0x0010
 #define SCTP_PR_SCTP_RTX 0x0020
@@ -443,6 +445,11 @@
   sctp_assoc_t assoc_id;
   uint32_t assoc_value;
 };
+struct sctp_stream_value {
+  sctp_assoc_t assoc_id;
+  uint16_t stream_id;
+  uint16_t stream_value;
+};
 struct sctp_paddrinfo {
   sctp_assoc_t spinfo_assoc_id;
   struct sockaddr_storage spinfo_address;
@@ -616,4 +623,10 @@
   uint16_t sas_instrms;
   uint16_t sas_outstrms;
 };
+enum sctp_sched_type {
+  SCTP_SS_FCFS,
+  SCTP_SS_PRIO,
+  SCTP_SS_RR,
+  SCTP_SS_MAX = SCTP_SS_RR
+};
 #endif