Add a new file VERSION to hold the current DPDK version number.
Have meson use this file for it's project version, and have make use
it for reporting out "showversion" and "showversionum".
Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Acked-by: Luca Boccassi <bluca@debian.org>
Reviewed-by: Rami Rosen <ramirose@gmail.com>