USB: isd200: don't include <linux/ide.h>

Now that commit 3794ade5

 removed
incorrect dependency on CONFIG_IDE we can fix the driver to not
include <linux/ide.h>:

* add ATA_REG_{ERROR,LCYL,HCYL,STATUS}_OFFSET defines and use them
  instead of IDE_{ERROR,LCYL,HCYL,STATUS}_OFFSET from <linux/ide.h>

* remove no longer needed <linux/ide.h> include

* remove incorrect comment added by the last commit:
  - isd200.c is not the only user of struct hd_driveid besides IDE
    (see drivers/block/xsysace.c and arch/um/drivers/ubd_kern.c)

Cc: Alan Cox <alan@redhat.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>