ARM: davinci: Explicitly set channel controllers' default queues

Davinci platforms may define a default queue for each channel
controller. If one is not defined, the default queue is set to EVENTQ_1.
However, there's no way to distinguish between an unset default queue to
one that is set to EVENTQ_0, as EVENTQ_0 = 0.

Explicitly specify the default queue for all channel controllers on all
Davinci platforms to EVENTQ_1, and don't overwrite it in the EDMA probe
function.

One exception is the DA850 board, for which EVENTQ_1 is not a valid
option for its second channel controller. Use EVENTQ_0 instead for that
channel controller.

Signed-off-by: Ido Yariv <ido@wizery.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>