A couple of patches for the ftdi_sio driver on 2.5.73

"2.5.73-ftdi_sio-bigupdate.patch" - this is a big, ugly patch to
bring the ftdi_sio driver in line with what recently submitted for
inclusion in the 2.4.x kernel
(v2.4/testing/cset/cset-abbotti@mev.co.uk|ChangeSet|20030627190202|35624.txt),
but with necessary changes for 2.5.x.  I've bumped the driver's
version number to 1.4.0 to distinguish it from that submitted for
the 2.4.x kernel.

"2.5.73-ftdi_sio-dynamicwrite.patch" - this adds to the above patch
to replace the pool of urbs used for writes with dynamically
allocated urbs and transfer buffers.  I've tested this on the
FT8U232AM and FT232BM and I think I've catered for the older "SIO"
device, but I don't have a device to test that.  Also, it is not
safe to unload the driver module while write urbs are in flight
(same as for the Visor driver).