(e)glibc-package: fix kernel version passed to qemu

(e)glibc-package: fix kernel version passed to qemu

Binary locale generation fails with

FATAL: kernel too old

if (e)glibc is configured for kernels newer than 2.6.16. This comes from
kernel version check in sysdeps/unix/sysv/linux/dl-osinfo.h. We configure
(e)glibc with "--enable-kernel=${OLDEST_KERNEL}", so to pass this check we
need kernel version reported from QEMU to (e)glibc be $OLDEST_KERNEL or higher.

Fix qemu "-r" parameter to match OLDEST_KERNEL.

Acked-by: Tom Rini <trini@embeddedalley.com>