bnxt_en: Refactor TX ring free logic

Add a new bnxt_hwrm_tx_ring_free() function to handle freeing a HW
transmit ring.  The new function will also be used in the next patch
to free the TX ring in queue_stop.

Reviewed-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Link: https://patch.msgid.link/20250213011240.1640031-10-michael.chan@broadcom.com


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