hpt366: clean up DMA timeout handling for HPT370

Clean up DMA timeout handling for HPT370:

- hpt370_lostirq_timeout() cleared the DMA status which made __ide_dma_end()
   called afterwards return the incorrect result, and the DMA engine was reset
   both before and after stopping DMA while the HighPoint drivers only do it
   after (which seems logical) -- fix this and also rename the function;

- get rid of the needless mutual recursion in hpt370_ide_dma_end() and
   hpt370_ide_dma_timeout();

- get rid of hpt370_lostirq_timeout() since hwif->ide_dma_end() called from
   the driver's interrupt handler later does all its work.

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>