This patch updates the MicroBlaze localplt.data based on the results
of a build with build-many-glibcs.py. This is simply an empirical
update; quite possibly the port could be optimized to remove more
local PLT entry usage.
Tested (compilation tests) with build-many-glibcs.py.
* sysdeps/unix/sysv/linux/microblaze/localplt.data (__pread64):
Add libc.so PLT entry.
(__tls_get_addr): Make ld.so PLT entry optional.