package/ply: new package

ply is a light-weight dynamic tracer for Linux. By means of using the
BPF it can attach probes to the linux kernel (e. g. kprobes).

It's a small alternative to LLVM based tracers for embedded systems.

Project page:
https://github.com/wkz/ply/releases

Documentation can be found here:
https://wkz.github.io/ply/



Tested with beaglebone_defconfig (uClibc-ng as well as glibc)

Signed-off-by: Andreas Klinger <ak@it-klinger.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>