These changes lay some of the ground work for supporting something
similar to FMA event under Solaris. In particular these changes
add or modify the following areas.
First off an implementation of the gethrestime() function is added
to libspl. Secondly, the missing type processorid_t has been added.
And finally the lib/libspl/include/sys/fm/{protocol.h|util.h} stub
headers have been removed in favor of updating the full versions
in module/zfs/include/sys/fm/{protocol.h|util.h} to work cleanly
in both user and kernel space.