access/ssa_prdb.c: Change field names to fit ib_acme output

The following PR field names were changed:
 - 'pk' -> 'pkey'
 - 'lid' -> 'dlid'
 - 'is_reversible' -> 'reversible'

Signed-off-by: Ilya Nelkenbaum <ilyan@mellanox.com>
Signed-off-by: Hal Rosenstock <hal@mellanox.com>
ssa_db_helper.h: API description fix

Using 'SSA DB' instead of 'SMDB', since
both PRDB and SMDB are handled.

Signed-off-by: Ilya Nelkenbaum <ilyan@mellanox.com>
Signed-off-by: Hal Rosenstock <hal@mellanox.com>