buildroot

zmqpp: use more logical way of expressing comment dependencies

In most packages, we use 'depends on !A || !B || !C' and not 'depends
on !(A && B && C)' to express the dependencies of comments on missing
toolchain features. As suggested by Yann E. Morin, let's switch zmqpp
to this convention.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>