bng_en: Add initial interaction with firmware

bng_en: Add initial interaction with firmware

Query firmware with the help of basic firmware commands and
cache the capabilities. With the help of basic commands
start the initialization process of the driver with the
firmware.
Since basic information is available from the firmware,
register with devlink.

Signed-off-by: Vikas Gupta <vikas.gupta@broadcom.com>
Reviewed-by: Bhargava Chenna Marreddy <bhargava.marreddy@broadcom.com>
Reviewed-by: Rajashekar Hudumula <rajashekar.hudumula@broadcom.com>
Link: https://patch.msgid.link/20250701143511.280702-5-vikas.gupta@broadcom.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>