Remove -m32 calls from op-builds.

Fixes open-power/hostboot#3.

Change-Id: I244936b16a4fc6e8ee0e5534a7b88fe431f4b086
Reviewed-on: http://gfw160.aus.stglabs.ibm.com:8080/gerrit/14398
Reviewed-by: Brian Silver <bsilver@us.ibm.com>
Tested-by: Jenkins Server
Reviewed-by: A. Patrick Williams III <iawillia@us.ibm.com>