mk: add missing preprocessor options

Some targets in mk/internal/rte.compile-pre.mk are calling CC or
HOSTCC without passing CPPFLAGS, EXTRA_CPPFLAGS or HOST_CPPFLAGS,
HOST_EXTRA_CPPFLAGS.
On Debian/Ubuntu builds this means that preprocessor flags set by the
dpkg-buildpackage environment, like hardening flags, are not
correctly passed to all objects builds.

Signed-off-by: Luca Boccassi <lboccass@brocade.com>
Acked-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>