dmaengine: Cleanup logging messages

Use a more current logging style.

Add pr_fmt to prefix dmaengine: to messages.
Convert printk(KERN_ERR to pr_err(.
Convert embedded function name use to "%s: ", __func__
Align arguments.

Original-patch-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>