software/ors-amarisoft: enb.jinja2.cfg: Switch internal ru.ru_type to be 'sunwave' for Sunwave M2RU Radio Unit

ru/libinstance and everything inside there already refer to that unit as 'sunwave'.
Do the same for uniformity in enb.cfg and because we already refer to Lopcomm
ORAN Radio Unit as just 'lopcomm'.

In the future, if we will need to distinguish different models of one
manufacturer, we could extend ru type to be e.g. manufacturer/model or do
something similar.

Template rendering is still done with ru='m2ru' coming from outside but
internally it is now ru.ru_type='sunwave' instead of ru.ru_type='m2ru'.