lvm2: fix m68k build error
Disable PIE for m68k as it is not supported.
Fixes following autobuild failures:
http://autobuild.buildroot.net/results/2f976292ddbb8eddb58cc978f209f4f445b5b756/
http://autobuild.buildroot.net/results/7a2b1eef06004886be28744bf1c53d027f8d0123/
Signed-off-by: Waldemar Brodkorb <wbx@openadk.org>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>