Elm helper: fix compilation against elementary.

There was an issue when compiling against elementary when EO_BETA_API
wasn't set. This commit fixes that.

Thanks to Kuuko for reporting.

legacy/elementary/src/bin/test_entry.c

@@ -1,6 +1,7 @@
 #ifdef HAVE_CONFIG_H
 # include "elementary_config.h"
 #endif
+#define EO_BETA_API
 #include <Elementary.h>
 
 static void

legacy/elementary/src/lib/elm_helper.h

@@ -78,6 +78,7 @@ elm_validator_regexp_free(Elm_Validator_Regexp *validator) EINA_ARG_NONNULL(1);
 EAPI Elm_Regexp_Status
 elm_validator_regexp_status_get(Elm_Validator_Regexp *validator) EINA_ARG_NONNULL(1);
 
+#ifdef EO_BETA_API
 /**
  * @brief The regex validator. Used as callback to validate event.
  *
@@ -102,6 +103,7 @@ elm_validator_regexp_status_get(Elm_Validator_Regexp *validator) EINA_ARG_NONNUL
  */
 EAPI Eina_Bool
 elm_validator_regexp_helper(void *data, Eo *obj, const Eo_Event_Description *desc, void *event_info);
+#endif
 
 /**
  * @}