net: ipv6: Add callbacks declarations to get access to IPv6 variables

Set up callbacks for main IPv6 variables ip6add, serverip6, gatewayip6
and set options to them in flag file. These variables are often set up by
users.

Signed-off-by: Viacheslav Mitrofanov <v.v.mitrofanov@yadro.com>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/include/env_callback.h b/include/env_callback.h
index 1eae0ef..85e7fe2 100644
--- a/include/env_callback.h
+++ b/include/env_callback.h
@@ -51,6 +51,15 @@
 #define NET_CALLBACKS
 #endif
 
+#ifdef CONFIG_IPV6
+#define NET6_CALLBACKS \
+	"ip6addr:ip6addr," \
+	"serverip6:serverip6," \
+	"gatewayip6:gatewayip6,"
+#else
+#define NET6_CALLBACKS
+#endif
+
 #ifdef CONFIG_BOOTSTD
 #define BOOTSTD_CALLBACK	"bootmeths:bootmeths,"
 #else
@@ -65,6 +74,7 @@
 	ENV_DOT_ESCAPE ENV_FLAGS_VAR ":flags," \
 	"baudrate:baudrate," \
 	NET_CALLBACKS \
+	NET6_CALLBACKS \
 	BOOTSTD_CALLBACK \
 	"loadaddr:loadaddr," \
 	SILENT_CALLBACK \
diff --git a/include/env_flags.h b/include/env_flags.h
index 313cb8c..718d727 100644
--- a/include/env_flags.h
+++ b/include/env_flags.h
@@ -67,6 +67,15 @@
 #define NET_FLAGS
 #endif
 
+#ifdef CONFIG_IPV6
+#define NET6_FLAGS \
+	"ip6addr:s," \
+	"serverip6:s," \
+	"gatewayip6:s"
+#else
+#define NET6_FLAGS
+#endif
+
 #ifndef CONFIG_ENV_OVERWRITE
 #define SERIAL_FLAGS "serial#:so,"
 #else
@@ -76,6 +85,7 @@
 #define ENV_FLAGS_LIST_STATIC \
 	ETHADDR_FLAGS \
 	NET_FLAGS \
+	NET6_FLAGS \
 	SERIAL_FLAGS \
 	CONFIG_ENV_FLAGS_LIST_STATIC