Kernel: Add the SO_OOBINLINE SOL_SOCKET-level option macro

This is not actually implemented, as we don't have any support for
out-of-band right now, but this is required for some ports to compile.

Kernel/API/POSIX/sys/socket.h

@@ -110,6 +110,7 @@ enum {
     SO_LINGER,
     SO_ACCEPTCONN,
     SO_DONTROUTE,
+    SO_OOBINLINE,
 };
 #define SO_RCVTIMEO SO_RCVTIMEO
 #define SO_SNDTIMEO SO_SNDTIMEO
@@ -127,6 +128,7 @@ enum {
 #define SO_LINGER SO_LINGER
 #define SO_ACCEPTCONN SO_ACCEPTCONN
 #define SO_DONTROUTE SO_DONTROUTE
+#define SO_OOBINLINE SO_OOBINLINE
 
 enum {
     SCM_TIMESTAMP,