Docs: Add a group of APIs for which group is not declared in elm_config

Summary:
Longpress
   elm_config_longpress_timeout_get
   elm_config_longpress_timeout_set
SotfCursor
   elm_config_softcursor_mode_set
   elm_config_softcursor_mode_get
Tooltips (Add in Elm_Tooltips)
   elm_config_tooltip_delay_get
   elm_config_tooltip_delay_set

Test Plan: make doc

Reviewers: cedric, Hermet, zmike, Jaehyun_Cho

Reviewed By: Jaehyun_Cho

Subscribers: #reviewers, #committers

Tags: #efl

Differential Revision: https://phab.enlightenment.org/D7093

src/lib/elementary/elm_config.h

@@ -957,6 +957,15 @@ EAPI Elm_Slider_Indicator_Visible_Mode elm_config_slider_indicator_visible_mode_
  * @}
  */
 
+/**
+ * @defgroup longpress_group Longpress
+ * @ingroup Elementary
+ *
+ * @brief Configuration for longpress events.
+ *
+ * @{
+ */
+
 /**
  * Get the duration for occurring long press event.
  *
@@ -973,6 +982,19 @@ EAPI double       elm_config_longpress_timeout_get(void);
  */
 EAPI void         elm_config_longpress_timeout_set(double longpress_timeout);
 
+/**
+ * @}
+ */
+
+/**
+ * @defgroup softcursor_group SotfCursor
+ * @ingroup Elementary
+ *
+ * @brief Configuration for softcursor.
+ *
+ * @{
+ */
+
 /**
  * Set the mode used for software provided mouse cursors inline in the window
  * canvas.
@@ -1000,6 +1022,15 @@ EAPI void         elm_config_softcursor_mode_set(Elm_Softcursor_Mode mode);
  */
 EAPI Elm_Softcursor_Mode elm_config_softcursor_mode_get(void);
 
+/**
+ * @}
+ */
+
+/**
+ * @ingroup Elm_Tooltips
+ * @{
+ */
+
 /**
  * Get the duration after which tooltip will be shown.
  *
@@ -1014,6 +1045,10 @@ EAPI double      elm_config_tooltip_delay_get(void);
  */
 EAPI void        elm_config_tooltip_delay_set(double delay);
 
+/**
+ * @}
+ */
+
 /**
  * Get the configured cursor engine only usage
  *