[Why]
The old aux interface goes through i2caux and the aux_engine
and engine function pointers.  The multiple layers of indirection
make it hard to tell waht is happening.  The aux algorithm
does not need to be this complicated: attempt to submit the
request.  If you get an ack (reply = 0), stop.  Otherwise,
retry, up to 7 times.

[How]
Add a new helper function in dce_aux that performs aux retries

Move the plumbing of the aux calling code into dce_aux

Add functions in ddc that redirect directly to dce_aux

Make all aux calls use these functions
Signed-off-by: David Francis <David.Francis@amd.com>
Reviewed-by: Harry Wentland <Harry.Wentland@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>