package/localedef: fix dependencies

package/localedef: fix dependencies

localedef needs bison to satisfy a .y.c rule to generate a parser for
plural forms, to ultimately generate data for the target. So we do not
want to depend on the host-provided bison; we want to build our own (for
reproducibility).

localedef is a host-only package, and dependencies are not inherited
from the target variant, so we need to make them explicit host
dependencies.

And move the assignment after all the download-related variables.

Reported-by: James Hilliard <james.hilliard1@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
Reviewed-by: Romain Naour <romain.naour@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>