Update the md5sum for fedora 20 ppc64

The current md5sum for fedora 20 ppc64 ISO is wrong.
This patch is to correct it.

Signed-off-by: Mike Qiu <qiudayu@linux.vnet.ibm.com>
Merge pull request #1506 from QiuMike/Update_the_md5sum_for_fedora_20_ppc64

Update the md5sum for fedora 20 ppc64