<sys/socket.h>: add constant for kernel TLS.

Bug: N/A
Test: builds
Change-Id: I53e8dde1131fec781bee5371c03d4eb54cab9722
diff --git a/libc/include/sys/socket.h b/libc/include/sys/socket.h
index bbde88b..e54dd65 100644
--- a/libc/include/sys/socket.h
+++ b/libc/include/sys/socket.h
@@ -288,6 +288,7 @@
 #define SOL_ALG 279
 #define SOL_NFC 280
 #define SOL_KCM 281
+#define SOL_TLS 282
 
 #define IPX_TYPE 1