isp.4: Improve HARDWARE for HW Relnotes + SPDX

Convert the supported hardware into a descending column list to improve
aesthetic, density, and utility on console and in the hardware release
notes. Move the section into alignment for predictability, and tag spdx.

MFC after: 3 days
Reviewed by: carlavilla, imp, mav
Approved by: carlavilla (mentor)
Differential Revision: https://reviews.freebsd.org/D49721

(cherry picked from commit d9bdf419b19f658a79a69168ad740cd95cdf3e5f)