Programming DMA mode may destroy current PIO mode setting so if
CONFIG_HPT34X_AUTODMA=n (the default case) make ide_tune_dma() fail
early by disabling all host DMA masks and re-tune PIO mode.

This fix doesn't help with the driver being broken but is needed
for some other changes.
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>