External libraries headers such as DPDK, libibverb, quicly, etc. should
not be packaged in vpp-dev RPM.
Only package headers from vpp/ and vom/ subdirs.
Change-Id: Ief1454bd1261c8cf4dcd3b105e28f6852439e896
Signed-off-by: Benoît Ganne <bganne@cisco.com>