ide: checkpatch.pl fixes for ide-timing.h

Also fix placement of comments in ide_timing_compute() while at it.

There should be no functional changes caused by this patch
(md5sum was verified to be the same before/after the patch).

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