ide-cd: convert to ide-atapi facilities

... and remove no longer needed cdrom_start_packet_command and
cdrom_transfer_packet_command.

Tested lightly with ide-cd and ide-floppy.

Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/ide-atapi.c b/drivers/ide/ide-atapi.c
index d6a50d6..e96c012 100644
--- a/drivers/ide/ide-atapi.c
+++ b/drivers/ide/ide-atapi.c
@@ -549,7 +549,10 @@
 	}
 
 	/* Set the interrupt routine */
-	ide_set_handler(drive, ide_pc_intr, timeout, expiry);
+	ide_set_handler(drive,
+			(dev_is_idecd(drive) ? drive->irq_handler
+					     : ide_pc_intr),
+			timeout, expiry);
 
 	/* Begin DMA, if necessary */
 	if (dev_is_idecd(drive)) {