ARM: PL08x: move ccfg into txd structure

The ccfg register is used to configure the channel parameters - the type
and direction of transfer, the flow control signal and IRQ mask enables.
The type and direction of transfer is known in the relevent prep_*
function where a txd is created.  The IRQ mask enables are always set,
and the flow control signals are always set when we start processing a
txd according to phychan->signal.

If we store the ccfg value in the txd structure, we can avoid modifying
platform data - and even having it in platform data at all.

So, remove it from platform data too.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>