Remove useless p2.inf from o.e.e4.ui.workbench.renderers.swt.cocoa

It was introduced via
d321fb9
most likely to workaround org.eclipse.swt host not mandating dependency
on the correct os/arch specific fragment. As SWT does that this is
useless and just generates issues with maven publishing. Pointed out in
eclipse-platform/eclipse.platform.releng.aggregator#3264 (comment)

Author: akurtakov