config: never link with pthread on Windows
config: never link with pthread on Windows

Even if pthread is provided by the toolchain, it is not needed for DPDK
on Windows, because internal shim is used. As a side-effect, this
enables cross-build with MinGW configured with non-POSIX thread library,
e.g. mcfgthread, which is the default on some distributions.

Signed-off-by: Dmitry Kozlyuk <622f8c4298455ea0ac8bf96da29b254c86170938@gmail.com>
Acked-by: Pallavi Kadam <04c73ddce9f45f6664a05521f1a0d9e2539b2e10@intel.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk