item_updater: sort ubi specific code

Add item_updater_helper and implement it in ubi and static layouts.

Tested: Build this repo on both Romulus and Witherspoon OK;
        Tested on Romulus and Witherspoon that code update works fine.

Change-Id: I706cfe63900f89bb41672dcc745b3483e06838c7
Signed-off-by: Lei YU <mine260309@gmail.com>
diff --git a/static/Makefile.am.include b/static/Makefile.am.include
index 7bcfcb2..1a5128a 100644
--- a/static/Makefile.am.include
+++ b/static/Makefile.am.include
@@ -1,2 +1,3 @@
 phosphor_image_updater_SOURCES += \
-	%reldir%/flash.cpp
+	%reldir%/flash.cpp \
+	%reldir%/item_updater_helper.cpp
diff --git a/static/item_updater_helper.cpp b/static/item_updater_helper.cpp
new file mode 100644
index 0000000..5cd8b9e
--- /dev/null
+++ b/static/item_updater_helper.cpp
@@ -0,0 +1,47 @@
+#include "item_updater_helper.hpp"
+
+namespace phosphor
+{
+namespace software
+{
+namespace updater
+{
+
+void Helper::clearEntry(const std::string& entryId)
+{
+    // Empty
+}
+
+void Helper::cleanup()
+{
+    // Empty
+}
+
+void Helper::factoryReset()
+{
+    // TODO
+}
+
+void Helper::removeVersion(const std::string& versionId)
+{
+    // Empty
+}
+
+void Helper::updateUbootVersionId(const std::string& versionId)
+{
+    // Empty
+}
+
+void Helper::enableFieldMode()
+{
+    // TODO
+}
+
+void Helper::mirrorAlt()
+{
+    // Empty
+}
+
+} // namespace updater
+} // namespace software
+} // namespace phosphor