[libadwaita/wip/exalm/1_0] split-button: Add missing Since: 1.0 comments

[Alexander Mikhaylenko <alexm src gnome org>]

commit 4c6eda84a18143a13d2b9e621c815f1bee5de371
Author: Alexander Mikhaylenko <alexm gnome org>
Date:   Tue Sep 21 00:04:54 2021 +0500

    split-button: Add missing Since: 1.0 comments

 src/adw-split-button.c | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/src/adw-split-button.c b/src/adw-split-button.c
index 9f620b6e..566ee475 100644
--- a/src/adw-split-button.c
+++ b/src/adw-split-button.c
@@ -401,6 +401,8 @@ adw_split_button_class_init (AdwSplitButtonClass *klass)
    * AdwSplitButton::clicked:
    *
    * Emitted when the button has been activated (pressed and released).
+   *
+   * Since: 1.0
    */
   signals[SIGNAL_CLICKED] =
     g_signal_new ("clicked",
@@ -417,6 +419,8 @@ adw_split_button_class_init (AdwSplitButtonClass *klass)
    *
    * This is an action signal. Applications should never connect
    * to this signal, but use the [signal@Adw.SplitButton::clicked] signal.
+   *
+   * Since: 1.0
    */
   signals[SIGNAL_ACTIVATE] =
     g_signal_new ("activate",