eth: bnxt: remove rss_ctx_bmap

Core will allocate IDs for the driver, from the range
[1, BNXT_MAX_ETH_RSS_CTX], no need to track the allocations.

Reviewed-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Link: https://patch.msgid.link/20240711220713.283778-6-kuba@kernel.org


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