Pull up following revision(s) (requested by nakayama in ticket #1344):

sys/dev/sysmon/sysmon.c: revision 1.30

Module class of sysmon_envsys, sysmon_wdog and sysmon_power is
MODULE_CLASS_DRIVER, not MODULE_CLASS_MISC.

Fix that invoking envsys without sysmon_envsys kernel module failes with:
WARNING: module error: incompatible module class for `sysmon_envsys' (1 != 3)

(martin)