ibacm/prov: Change the provider to use the core SA access functions

ibacm/prov: Change the provider to use the core SA access functions

This patch enables the default provider to access the SA through
helper functions in the core instead of the verbs interface.
Major changes:

(1) Join the multicast group through the new core SA interface;
(2) Get path record through the new core SA interface;
(3) Remove the code to open umad interface in the default provider;
(4) Remove the sa_depth option in the default provider.

Signed-off-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Sean Hefty <sean.hefty@intel.com>