kernel: Add extern "C" to kernel_struct.h

Add extern "C" to kernel_struct.h to allow linkage in cpp.

Signed-off-by: Marcin Zwierz <[email protected]>

Author: Zzzwierzak

include/kernel_structs.h

@@ -30,6 +30,10 @@
 #include <arch/structs.h>
 #endif
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #define K_NUM_PRIORITIES \
 	(CONFIG_NUM_COOP_PRIORITIES + CONFIG_NUM_PREEMPT_PRIORITIES + 1)
 
@@ -230,6 +234,10 @@ struct _timeout {
 #endif
 };
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* _ASMLANGUAGE */
 
 #endif /* ZEPHYR_KERNEL_INCLUDE_KERNEL_STRUCTS_H_ */