net: Add NET_WAIT_FOREVER symbol to be used as timeout in network APIs

If a network API expects a millisecond timeout, then NET_WAIT_FOREVER
symbol can be used to indicate that the timeout should last forever.

Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>

include/net/net_core.h

@@ -20,6 +20,8 @@
 #include <sys/__assert.h>
 #include <kernel.h>
 
+#include <net/net_timeout.h>
+
 #ifdef __cplusplus
 extern "C" {
 #endif

include/net/net_timeout.h

@@ -28,6 +28,12 @@
 extern "C" {
 #endif
 
+/**
+ * Symbol to indicate that the caller wants the timeout to be waited forever.
+ * This can be used when a network API expects a millisecond timeout.
+ */
+#define NET_WAIT_FOREVER (-1)
+
 /** Let the max timeout be 100 ms lower because of
  * possible rounding in delayed work implementation.
  */