RDMA/ocrdma: Fix EQ destroy failure during driver unload

Changing the destroy sequence of mailbox queue and event queues.
FW expects mailbox queue to be destroyed before desroying the EQs.

Signed-off-by: Selvin Xavier <selvin.xavier@avagotech.com>
Signed-off-by: Devesh Sharma <devesh.sharma@avagotech.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>