MFC r364359, r364360, r364361, r364362, r364364, r364370

r364359 | imp | 2020-08-18 15:26:39 -0600 (Tue, 18 Aug 2020) | 9 lines

Move the possible event types into a column table to make it easier to read.

Sort system type alphabetically.
Remove some commas that aren't in the devd notification messages.

MFC After: 3 days
Reviewed by: 0mp (earlier versions), jhb (useful feedback on earlier versions)
Differential Revision: https://reviews.freebsd.org/D26105

r364360 | imp | 2020-08-18 15:26:45 -0600 (Tue, 18 Aug 2020) | 4 lines

GEOM::rotation_rate changes are also signaled via devctl.

MFC After: 3 days

r364361 | imp | 2020-08-18 15:26:50 -0600 (Tue, 18 Aug 2020) | 8 lines

Document the PMU system

The pmu(4) and adb(4) drivers on powerpc generate PMU events. Document them.

The allwinner power modules also generate these events. Document those as well.

MFC After: 3 days

r364362 | imp | 2020-08-18 15:26:54 -0600 (Tue, 18 Aug 2020) | 4 lines

Document the AEON subsystem for the Amiga's power button.

MFC After: 3 days

r364364 | imp | 2020-08-18 15:42:02 -0600 (Tue, 18 Aug 2020) | 5 lines

Fix two typos.

Submitted by: rpokala@
MFC After: 3 days

r364370 | imp | 2020-08-18 20:18:11 -0600 (Tue, 18 Aug 2020) | 8 lines

Three typos:
Amiga is a proper noun
Condition is traditionally spelled starting with 'c'
Some, but not all, of the over/under-voltage instances were hyphenated.
Since they are all adverb phrases, they all need to be hyphenated.

Pointy hat: imp