configure uses "pkg-config" directly so that GLIB_VERSION is always based
on host glib version.   To correctly handle cross-compilation it should use
"$pkg_config" and take GLIB_VERSION from the cross-compiled glib.

Reported-by: Валентин <val15032008@mail.ru>
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1414


Cc: qemu-stable@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>