package/volk: needs C++17, not boost

Since volk 2.5.1, C++17 is required, and no Boost component is used
anymore.

Signed-off-by: Gwenhael Goavec-Merou <gwenhael.goavec-merou@trabucayre.com>
[yann.morin.1998@free.fr: split out to its own patch]
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>