glibc: both eglibc and glibc need host-gawk

Until now, only the eglibc build was pulling host-gawk as a
dependency, but after more testing, it turns out that the glibc build
also requires host-gawk.

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