Update smartpqi(4) to document the dev.smartpqi.<unit>.debug_level
sysctl for runtime debug level changes, and note that device
add/remove and controller event messages always appear in dmesg
regardless of the debug_level setting.
PR: 294161
Reviewed by: imp
Approved by: imp
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D56832
John Hall
e9912b7e88