tmscsim: remove procfs write support from tmscsim

From: Christoph Hellwig <hch@lst.de>

When looking at the driver after reviewing the changes I stubled over
that code.  Almost all of the funcitonality (except DUMP) should go
through the midlayer and will at least cause some confusion if it
doesn't.

Also the implementation isn't exactly nice, like kmalloced scsi commands
and the tytpical 'parsing' macros cut & pasted over all historic scsi
drivers.  I think we're better of removing it completly and maybe readd
dump as a sysfs attribute if needed.

500 lines of code gone.