Shared receive queue (SRQ) is defined as a pool of
receive buffers shared among multiple QPs which belong
to same protection domain in a given process context.
Use of SRQ reduces the memory foot print of IB applications.

Broadcom adapters support SRQ, adding code-changes to enable
shared receive queue.
Signed-off-by: NDevesh Sharma <devesh.sharma@broadcom.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>