UFS provisioning and usage improvements

The UFS provisioning support is brough up to date. The default handling
of requests to flash missing files is changed to fail the flashing, to
avoid mistakes with partially flashed builds. Usage help text is
updated to better match the implementation.

Ramdump, libusb and lots of improvements

It's been almost 7 years since v1.0. We've gained UFS provisioning
support, transition to UFBFS and later libusb, ramdump support,
kickstart support, and a ton of fixes.

firehose: Read back max payload size

The max payload size is negotiated through the configure and configure
response messages. Update the max payload size based on the
configuration response value, if present.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>