reenable microblaze little endian for internal musl toolchain

The assumption that musl libc does not support microblaze
little endian mode is wrong. See
http://git.musl-libc.org/cgit/musl/tree/configure

 line
number 447-448.

Tested with qemu. Just revert previous commit as suggested by
Thomas Petazzoni.

Signed-off-by: Waldemar Brodkorb <wbx@openadk.org>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>