procps: support ptest when TCLIBC is glibc

procps: support ptest when TCLIBC is glibc

* support ptest for procps TCLIBC is glibc. The configure.ac only match
  LINUX as "linux-gnu", we can patch it to make test can run on musl lib
system, but the upstream testsuite should only run on gnu libc host,
some test cases only suitable for glibc, eg: Some of the error messages
for free command on musl system is not the same as glibc system, which
will make test failed. In order to avoid some other unexpected failure,
just support ptest for glibc.

* procps's testsuite use DejaGnu test framework.  The testsuite is
  expected to run during build time, this implementation create the same
folder structure as the testsuite expected to make it can work well.

Signed-off-by: Changqing Li <changqing.li@windriver.com>
Signed-off-by: Antonin Godard <antonin.godard@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>