bnxt_en: Refactor ring reservation functions

The current functions to reserve hardware rings pass in 6 different ring
or resource types as parameters.  Add a structure bnxt_hw_rings to
consolidate all these parameters and pass the structure pointer instead
to these functions.  Add 2 related helper functions also.  This makes
the code cleaner and makes it easier to add new resources to be
reserved.

Reviewed-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
Reviewed-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>