Updated xpath pointing to a module instance under services subtree.

Updated xpath pointing to a module instance under services subtree.

From /config/modules/module[name='hash-map-data-store']/instance[name='hash-map-data-store']
To   /modules/module[type=hash-map-data-store][name=hash-map-data-store']

Affected netconf operations: get-config, edit-config.
Backwards compatibility with previous xpath version is preserved.

Change-Id: Ic7c8057811001dbec34115b3745ce42bae790a45
Signed-off-by: Maros Marsalek <mmarsale@cisco.com>