bng_en: Add initial support for CP and NQ rings

bng_en: Add initial support for CP and NQ rings

Allocate CP and NQ related data structures and add support to
associate NQ and CQ rings. Also, add the association of NQ, NAPI,
and interrupts.

Signed-off-by: Bhargava Marreddy <bhargava.marreddy@broadcom.com>
Reviewed-by: Vikas Gupta <vikas.gupta@broadcom.com>
Reviewed-by: Rajashekar Hudumula <rajashekar.hudumula@broadcom.com>
Link: https://patch.msgid.link/20250919174742.24969-4-bhargava.marreddy@broadcom.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>