Use BUILD_ARCH instead to check ppc endianes

Build workers are BigEndian, so we can't rely on uname output. Let use
BUILD_ARCH instead.

Signed-off-by: Dinar Valeev <dvaleev@suse.com>
Don't enable virtio for ppc64le

ATM virtio is broken for LE guests on Power KVM. Use vscsi for now.

Signed-off-by: Dinar Valeev <dvaleev@suse.com>
Don't set HOST_ARCH to ppc970 on other hosts

Last commit introduced regression. Fixinig...

Signed-off-by: Dinar Valeev <dvaleev@suse.com>
- fix typo in ppc64le setup
- fix kvm setup for ppc64le system
mkbaselibs: don't mark symlinks as %dir