delete (now) trivial poms""

This reverts commit 81f7a13cc4a4cddcb893935483dc0e5264c2c2ff.

With https://github.com/eclipse-platform/eclipse.platform.releng.aggregator/pull/448
the eclipse-platform-parent pom does configure the 'format' property of
the 'tycho-packaging-plugin' anymore and uses the new
'tycho.buildqualifier.format' property instead. This makes the reverted
commit obsolet.