IDE: Coding Style fixes to drivers/ide/pci/cmd640.c

Fix all the errors and a few warnings.
Compile tested.

[bart: some fixes, md5sum checked]

Signed-off-by: Paolo Ciarrocchi <paolo.ciarrocchi@gmail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>