ide: make void and rename ide_dma_timeout() method

ide: make void and rename ide_dma_timeout() method

Since ide_dma_timeout() method's result is discarded, make it return 'void'.
While at it, drop 'ide_' from the method's name, drop the '__' prefix from
the default method's name, and do some cleanups in this method driver-wise:

- in ide-dma.c, au1xxx-ide.c, and pdc202xx_old.c, define/use 'hwif' variable;

- in au1xxx-ide.c, get rid of commented out printk();

- in sl82c105.c, get rid of unnecessary variables.

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>