image: Add a function to modify category information

Add a generic function which can check whether a category has an
entry ID.

Signed-off-by: Naoki Hayama <naoki.hayama@lineo.co.jp>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/common/image.c b/common/image.c
index 645bfef..4fc4a0f 100644
--- a/common/image.c
+++ b/common/image.c
@@ -859,6 +859,24 @@
 }
 
 /**
+ * genimg_cat_has_id - check whether category has entry id
+ * @category: category to look up (enum ih_category)
+ * @id: entry id to be checked
+ *
+ * This will scan the translation table trying to find the entry that matches
+ * the given id.
+ *
+ * @return true if category has entry id; false if not
+ */
+bool genimg_cat_has_id(enum ih_category category, uint id)
+{
+	if (get_table_entry(table_info[category].table, id))
+		return true;
+
+	return false;
+}
+
+/**
  * get_table_entry_name - translate entry id to long name
  * @table: pointer to a translation table for entries of a specific type
  * @msg: message to be returned when translation fails
diff --git a/include/image.h b/include/image.h
index 10995b8..00f774f 100644
--- a/include/image.h
+++ b/include/image.h
@@ -568,6 +568,15 @@
  */
 const char *genimg_get_cat_desc(enum ih_category category);
 
+/**
+ * genimg_cat_has_id() - Check whether a category has an item
+ *
+ * @category:	Category to check
+ * @id:		Item ID
+ * @return true or false as to whether a category has an item
+ */
+bool genimg_cat_has_id(enum ih_category category, uint id);
+
 int genimg_get_os_id(const char *name);
 int genimg_get_arch_id(const char *name);
 int genimg_get_type_id(const char *name);