LU-6850 lnet: remove references to ib_reg_phys_mr()

LU-6850 lnet: remove references to ib_reg_phys_mr()

Removed references to ib_reg_phys_mr() and PMR which were added
to deal with some Chelsio specific scenario, but are no longer needed.

Signed-off-by: Amir Shehata <amir.shehata@intel.com>
Change-Id: I07fc8e66e5bb0ade286761612b9b878fae34c183
Reviewed-on: http://review.whamcloud.com/15788
Tested-by: Jenkins
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Frank Zago <fzago@cray.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>