net/qede/base: support doorbell overflow recovery

Add support for doorbell overflow recovery mechanism:
The doorbell recovery mechanism consists of a list of entries which
represent doorbelling entities (l2 queues, roce sq/rq/cqs, the slowpath
spq, etc). Each entity needs to register with the mechanism and provide
the parameters describing it's doorbell, including a location where last
used doorbell data can be found. The doorbell execute function will
traverse the list and doorbell all of the registered entries.

Signed-off-by: Rasesh Mody <rasesh.mody@cavium.com>