Add support for probing the SCSI VPD Extended Inquiry page (0x86).

This VPD page is effectively an extension of the standard Inquiry
data page, and includes lots of additional bits.

This commit includes support for probing the page in the SCSI probe code,
and an additional request type for the XPT_DEV_ADVINFO CCB. CTL already
supports the Extended Inquiry page.

Support for querying this page in the sa(4) driver will come later.

sys/cam/scsi/scsi_xpt.c:
Probe the Extended Inquiry page, if the device supports it, and
return it in response to a XPT_DEV_ADVINFO CCB if it is requested.

sys/cam/scsi/cam_ccb.h:
Define a new advanced information CCB data type, CDAI_TYPE_EXT_INQ.

sys/cam/cam_xpt.c:
Free the extended inquiry data in a device when the device goes
away.

sys/cam/cam_xpt_internal.h:
Add an extended inquiry data pointer and length to struct cam_ed.

sys/sys/param.h
Bump __FreeBSD_version for the addition of the new
CDAI_TYPE_EXT_INQ advanced information type.

Sponsored by: Spectra Logic
MFC after: 1 week