acinclude: Also use LIBS from dpkg pkg-config

acinclude: Also use LIBS from dpkg pkg-config

DPDK 18.11 builds using the more modern meson build system no more
provide the -ldpdk linker script. Instead it is expected to use
pkgconfig for linker options as well.

This change will set DPDK_LIB from pkg-config (if pkg-config was
available) and since that already carries the whole-archive flags
around the PMDs skips the further wrapping in more whole-archive
if that is already part of DPDK_LIB.

To work reliable in all environments this needs pkg-config 0.29.1.
We want to be able to use PKG_CHECK_MODULES_STATIC which
is not yet available in 0.24. Therefore update pkg.m4
to pkg-config 0.29.1.

This should be backport-safe as these macro files are all versioned.
autoconf is smart enough to check the version if you have it locally,
and if the system's is higher, it will use that one instead.

Acked-by: Luca Boccassi <bluca@debian.org>
Acked-by: Aaron Conole <aconole@redhat.com>
Signed-off-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
Signed-off-by: Ian Stokes <ian.stokes@intel.com>