usb: dwc3: patches for v3.6 merge window

lots of changes for the dwc3 driver which will make
the driver a lot more stable and some changes which
are just cosmetic.

The bulk of changes is related to mis-defined macros
which were never used before, some fixes to error path
which e.g. prevent the driver from initiating two
transfer on ep0out in case of stall, some fixes to
request dequeueing and the End Transfer Command.

We have some changes to U1/U2 handling where we were
enabling those transtions at the wrong spot (though
we haven't seen a problem from that as of today).

A few patches will make it easier to add support for
newer releases of the core by adding definitions for
new registers and changing the code to act accordingly
when certain revisions are detected.

There's also the usual comestic changes to make the
driver easier to maintain and make it easier for new-
comers to understand the driver. Also one patch fixing
a double inclusion of a header.