isp(4): Use the FLT on all supported controllers

The ISP26xx based HBAs are left as is for now with static NVRAM addressing.
Those HBAs are known as 83xx (2031 and 8031 for real) and need special handling.
This is left for further investigation for now.

Cosmetics:

• rename functions and defines as they are no longer specific to 28xx
• set reasonable log levels
• sort FLT and NVRAM functions (in the order they are used)

Tested and approved to work on real hardware with:

• Qlogic ISP 2532 (QLogic QLE2562 8Gb 2Port FC Adapter)
• Qlogic ISP 2722 (QLogic QLE2690 16Gb FC Adapter)
• Qlogic ISP 2812 (QLogic QLE2772 32Gbit 2Port FC Adapter)

PR: 271062
Reviewed by: imp, mav
Sponsored by: Technical University of Munich
Pull Request: https://github.com/freebsd/freebsd-src/pull/726

(cherry picked from commit 707e4d1b20aa3983f7cd2f444d6ce41eebc02698)