I had a similar question this days and I tried to see if the features module could help. Features worked to me.
You can create the field by the UI and then export a feature with the address field already created.
After that you can move the inc files for your custom module and add an include on your .module file:
include_once('[your_module].features.inc');
Then you will need to add the some lines on your .info from the info file of the exported feature.
Your info file will need something like this:
dependencies[] = "features"
dependencies[] = "text"
features[field][] = "node-article-field_address"
This question may help you too.
Develop a module that adds a new content type with custom fields