test: skip meson dependency checks if not required
test: skip meson dependency checks if not required

Don't need to check dependencies if test apps will not be built anyway.

Signed-off-by: Ilya Maximets <e6f59449982e74b9a8013e88011af79c397f66d7@samsung.com>
Acked-by: Bruce Richardson <66b9e8e8fbd5e9f41f91b0af050876182ce9d0e4@intel.com>
Acked-by: Aaron Conole <aa17ba42a0685b214660ffb377dc7569a94d48c9@redhat.com>
Acked-by: Luca Boccassi <020748dc039465edc3ee6f30c530b21164cdce27@debian.org>

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