package/localedef: add missing dependeny on host-gawk

package/localedef: add missing dependeny on host-gawk

While reviewing the patch [1], we noticed that host-gawk dependency
was missing. It may trigger an issue if gawk is missing on the host
since it's a "critical tool" [2].

Indeed, localedef package is actually glibc sources that check gawk
host binary.

host-gawk is listed in glibc package dependency [3], so add it to
localedef too.

[1] af90a104c06542a1bf5545eaf9b9c7beb7176e80
[2] https://sourceware.org/git/?p=glibc.git;a=blob;f=configure.ac;h=49b900c1ed68fa4dd1dadca809ceb6e8b237a89c;hb=9ea3686266dca3f004ba874745a4087a89682617#l1021
[3] https://git.buildroot.net/buildroot/tree/package/glibc/glibc.mk?h=2020.02#n38

Signed-off-by: Romain Naour <romain.naour@gmail.com>
Cc: Yann E. MORIN <yann.morin.1998@free.fr>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>