IB/PVRDMA: Rename ib_ah_attr related functions

Functions pvrdma_ah_attr_to_ib and ib_ah_attr_to_pvrdma have
been renamed so they are in sync wit the rename of the
ib_ah_attr structure

Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Don Hiatt <don.hiatt@intel.com>
Reviewed-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Dasaratharaman Chandramouli <dasaratharaman.chandramouli@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>