Legacy IDE VLB host drivers didn't check for "probe" options when compiled
as modules, which was obviously wrong as we don't want module to poke at
random I/O ports by simply loading it.  Fix it by adding "probe" module param
to legacy IDE VLB host drivers.

v2:
* don't obsolete old "ide0=dtc2278/ht6560b/qd65xx/ali14xx/umc8672"
  IDE driver options yet (per Alan Cox's request) and enhance documentation
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>