gettext: Fix sysroot conflict over owner of macros

gettext: Fix sysroot conflict over owner of macros

gettext-minimal-native andgettext-native are trampling over each other's files. This can
be reproduced with:

bitbake gettext-minimal-native
bitbake gettext-native
bitbake gettext-native -c clean
bitbake shadow-native

which will fail since the aclocal gettext macros will have disappeared. This patch
fixes the problem by giving ownership of them to gettext-minimal-native and ensuring
there is a correct dependency on this.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>