This change:
* Removes "options PERFCTRS", the associated includes, and the associated
ifdefs. In doing so, it removes several XXXSMPs in the MI code, which is
good.
* Removes the PMC code of ARM XSCALE.
* Removes all the pmc.h files. They were all empty, except for ARM XSCALE.
* Reorders the x86 PMC code not to rely on the legacy pmc.h file. The
definitions are put in sysarch.h.
* Removes the kern/sys_pmc.c file, and along with it, the sys_pmc_control
and sys_pmc_get_info syscalls. They are marked as OBSOL in kern,
netbsd32 and rump.
* Removes the pmc_evid_t and pmc_ctr_t types.
* Removes all the associated man pages. The sets are marked as obsolete.
62c8988166