bnxt: Update man page with newly supported devices, options, etc

update man page with

• Newly supported devices
• Newly added options
• 'maintained by' Email ID

Submitted by: Siva Kallam <siva.kallam@@broadcom.com>
Reviewed by: shurd, sbruno
Approved by: shurd
Sponsored by: Broadcom Limited
Differential Revision: https://reviews.freebsd.org/D13982