IB/qib: Remove dma.c and use rdmavt version of dma functions

This patch removes the qib_dma.c file and uses the version which has been
added to rdmavt.

Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/qib/qib_verbs.h

@@ -1182,6 +1182,4 @@ extern unsigned int ib_qib_max_srq_wrs;
 
 extern const u32 ib_qib_rnr_table[];
 
-extern struct ib_dma_mapping_ops qib_dma_mapping_ops;
-
 #endif                          /* QIB_VERBS_H */