ide: add device flags

Add 'unsigned long dev_flags' to ide_drive_t and convert bitfields
to IDE_DFLAG_* flags.

While at it:
- IDE_DFLAG_ADDRESSING -> IDE_DFLAG_LBA48
- fixup some comments
- remove needless g->flags zeroing from ide*_probe()

There should be no functional changes caused by this patch.

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/legacy/ht6560b.c b/drivers/ide/legacy/ht6560b.c
index 5123ea2..c7e5c22 100644
--- a/drivers/ide/legacy/ht6560b.c
+++ b/drivers/ide/legacy/ht6560b.c
@@ -120,7 +120,8 @@
 	 * Need to enforce prefetch sometimes because otherwise
 	 * it'll hang (hard).
 	 */
-	if (drive->media != ide_disk || !drive->present)
+	if (drive->media != ide_disk ||
+	    (drive->dev_flags & IDE_DFLAG_PRESENT) == 0)
 		select |= HT_PREFETCH_MODE;
 
 	if (select != current_select || timing != current_timing) {
@@ -249,11 +250,11 @@
 	 */
 	if (state) {
 		drive->drive_data |= t;   /* enable prefetch mode */
-		drive->no_unmask = 1;
-		drive->unmask = 0;
+		drive->dev_flags |= IDE_DFLAG_NO_UNMASK;
+		drive->dev_flags &= ~IDE_DFLAG_UNMASK;
 	} else {
 		drive->drive_data &= ~t;  /* disable prefetch mode */
-		drive->no_unmask = 0;
+		drive->dev_flags &= ~IDE_DFLAG_NO_UNMASK;
 	}
 
 	spin_unlock_irqrestore(&ht6560b_lock, flags);