Add docs for some internal methods

Doxygen headers added for XkbGetCoreMap() and XkbSetRepeatKeys()

Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1851>

include/xkbsrv.h

@@ -467,8 +467,21 @@ extern _X_EXPORT void XkbUpdateActions(DeviceIntPtr /* pXDev */ ,
                                        XkbEventCausePtr /* cause */
     );
 
-extern _X_EXPORT KeySymsPtr XkbGetCoreMap(DeviceIntPtr  /* keybd */
-    );
+/**
+ * @brief get the current keysym map
+ *
+ * This call might be used after a keyboard mapping has been reloaded
+ * with InitKeyboardDeviceStruct() to get the information needed to
+ * pass to XkbApplyMappingChange()
+ *
+ * The returned value is dynamically allocated, and must be
+ * freed after use.
+ *
+ * @param keybd  Keyboard to use to get the map
+ *
+ * @return keysym map, or NULL if an error occurs
+ */
+extern _X_EXPORT KeySymsPtr XkbGetCoreMap(DeviceIntPtr keybd);
 
 extern _X_EXPORT void XkbApplyMappingChange(DeviceIntPtr /* pXDev */ ,
                                             KeySymsPtr /* map */ ,
@@ -723,10 +736,28 @@ extern _X_EXPORT void XkbDisableComputedAutoRepeats(DeviceIntPtr /* pXDev */ ,
                                                     unsigned int        /* key */
     );
 
-extern _X_EXPORT void XkbSetRepeatKeys(DeviceIntPtr /* pXDev */ ,
-                                       int /* key */ ,
-                                       int      /* onoff */
-    );
+/**
+ * @brief Set global autorepeat / sync core protocol repeat flags
+ *
+ * This call performs one of two actions, depending on whether
+ * key is set to -1 or not.
+ *
+ * If the key is set to -1, the global autorepeat setting is
+ * set to the value specified in the onoff parameter.
+ *
+ * If the key is a keycode, the XKB repeat setting for the key is
+ * synchronised from the core protocol setting, and the onoff
+ * parameter is ignored.
+ *
+ * @param pxDev Keyboard to use
+ * @param key   Keycode, or -1
+ * @param onoff One of { AutoRepeatModeOff, AutoRepeatModeOn }
+ *              Used only if key == -1
+ *
+ */
+extern _X_EXPORT void XkbSetRepeatKeys(DeviceIntPtr pXDev,
+                                       int key,
+                                       int onoff);
 
 extern _X_EXPORT int XkbLatchModifiers(DeviceIntPtr /* pXDev */ ,
                                        CARD8 /* mask */ ,