Revert r264907 and r264908:

Restore make-memstick.sh back to its original state to
unbreak booting for machines that do not support GPT.

I have in-progress work to keep the MBR layout and add
the EFI partition, but it is not yet ready, and does
need at least one full release build to be certain it
does not break.

Sponsored by:	The FreeBSD Foundation
Remove device type from the uftdi_devs table, enhance the jtag-skip feature.

Device type and revision is now determined from the bcdDevice field and
doesn't need to be in the table at all.  The feature that skips creation
of /dev/ttyU* entries for jtag and gpio interfaces is enhanced:

 - The feature is now optional, but enabled by default.  A tunable and
   sysctl are available to control it: hw.usb.uftdi.skip_jtag_interfaces.
 - We no longer assume interface #0 is the only jtag interface.  Up to
   eight interfaces per chip can be flagged as jtag.  (Current ftdi chips
   support a max of 4 interfaces; this leaves room for growth.)
 - Some manufacturers don't change the product ID or use the same ID for
   different devices intended for both serial-comms and jtag/gpio use.
   Often while the product ID is the same, the product name string is
   different, so it's now possible to search for the product name in a
   table of strings and get the set of non-tty interfaces from that table.