(split) The pmap function pmap_clear_reference() is no longer used.  Remove it.

pmap_clear_reference() has had exactly one caller in the kernel for
several years, more precisely, since FreeBSD 8.  Now, that call no
longer exists.

Approved by:	re (kib)
Sponsored by:	EMC / Isilon Storage Division
(split) Add new USB ID.

PR:		usb/182936
Submitted by:	Keith White <kwhite@site.uottawa.ca>
MFC after:	1 week
(split) Merge branch 'CURRENT' (commit 'b9099489')