cxgb4: Support for user mode bar2 mappings with T4

Enhance cxgb4_t4_bar2_sge_qregs() and cxgb4_bar2_sge_qregs() to support T4
user mode mappings.  Update all the current users as well.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>