main/postmarketos-ui-*: fix tinydm-openrc depend

Let all packages depending on tinydm depend on tinydm-openrc too. This is needed to make sure that tinydm-openrc is installed, before the tinydm service is enabled in the UI's post-install scripts.

This was not an issue because tinydm currently depends on tinydm-openrc. But that's a hack and will be removed when upstreaming tinydm to alpine.

Related: !1807 (closed)