bnxt_en: Add support for user configured RSS key

Store the user configured or generated Toeplitz key in
bp->rss_hash_key.  The key stays constant across ifdown/ifup
unless updated by the user.

Signed-off-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Link: https://lore.kernel.org/r/20240205223202.25341-12-michael.chan@broadcom.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>