perf: Make built-in libtraceevent plugins cohabit with external libtraceevent

This will package the plugins built by perf into kernel specific dir
under libdir, so it does not conflict with plugins from newly added
libtraceevent recipe

Fixes
do_sdk_depends: The file /usr/lib/traceevent/plugins/plugin_cfg80211.so is installed by both perf and libtraceevent, aborting

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Cc: Max Krummenacher <max.krummenacher@toradex.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>