core: Remove the ib_reg_phys_mr() and ib_rereg_phys_mr() verbs

The verbs are obsolete. The ib_rereg_phys_mr() verb is not used by
kernel ULPs, and the last ib_reg_phys_mr() call site in the kernel
tree has now been removed.

Two staging tree call sites remain in the Lustre client. The Lustre
team has been notified of the deprecation of reg_phys_mr.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Acked-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>