This restores the functionality as it was pre-97d152698f48.
A stopgap was committed by glebius@ in 34dfccc64f47 ("acpi: in
acpi_stype_sysctl() use same logic as in acpi_sleep_state_sysctl()").
PR: 290651
Fixes: 97d152698f48 ("acpi: Use sleep types defined in sys/power.h")
Sponsored by: The FreeBSD Foundation
(I have fixed some typos in here too, which I'll commit separately.)