Evas filters: Remove undocumented files from Doxygen

Some files had Doxygen tags @file, which included them in the
Files list. But they are not documented, so remove them from
the index.

src/lib/evas/filters/evas_filter.c

@@ -1,6 +1,7 @@
-/**
- * @file evas_filter.c
- * @brief Infrastructure for simple filters applied to RGBA and Alpha buffers.
+/*
+ * \@file evas_filter.c
+ *
+ * Infrastructure for simple filters applied to RGBA and Alpha buffers.
  * Originally used by font effects.
  *
  * Filters include:
@@ -9,6 +10,8 @@
  * - Displacement maps
  * - Color curves
  * - Blending and masking
+ *
+ * The reference documentation can be found in evas_filter_parser.c
  */
 
 #include "evas_filter.h"

src/lib/evas/filters/evas_filter_bump.c

@@ -1,8 +1,4 @@
-/**
- * @brief Simple bump maps algorithms for the software engine
- * @file evas_filter_bump.c
- * @author Jean-Philippe ANDRE <jpeg@videolan.org>
- */
+/* Simple bump map algorithms for the software engine */
 
 #include "evas_common_private.h"
 #include "evas_private.h"

src/lib/evas/filters/evas_filter_utils.c

@@ -1,6 +1,4 @@
-/** @file evas_filter_utils.c
- * @brief Utility functions for the filters.
- */
+/* Utility functions for the filters.  */
 
 #include "evas_filter_private.h"