doc: Makefile: Remove latex_paper_size (PAPER) option

This configuration variable was removed in Sphinx 1.6:
http://www.sphinx-doc.org/en/master/changes.html#id35. I suspect no one
might be using it. It could still be passed in SPHINXOPTS if needed.

Maybe the paper size should be set from Python instead:
http://www.sphinx-doc.org/en/master/usage/configuration.html

Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
1 file changed