Fix meson.build dependencies

Fix meson.build dependencies

In some environments, the compile command does not have "-ldl"
default. Add dl deps in meson.build to avoid compilation failures
in these environments.

Also add rte_bus_pci, which is a dependency for rte_pmd_ring or
rte_net_ring, and was triggering linker warning.

Signed-off-by: Long Wu <long.wu@corigine.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Chaoyong He <chaoyong.he@corigine.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@corigine.com>
Signed-off-by: Patrice Buriez <patrice.buriez@chenapan.org>
Change-Id: I7ecb825ff532f1b63f79bff93470fa9203906aca