added workaround for DMA IRQ issue.
(DMA only seems to create and Interrupt if it is the last in sequence!!!)

added parameter to enable/disable prepared message support

and also added first part of DMA-scheduling support

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
removed conditionals that were used during debugging
moved the "where_we_are" to only get scheduled once - reducing DMAs

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
prior to moving to transfer interface...
added "patch" to work arround  new HW bug that DEASSERTS CS momentarily
when resetting the TX buffer