ide: ide-cd.c fix sparse endianness warnings

drivers/ide/ide-cd.c:1276:46: warning: Using plain integer as NULL pointer
drivers/ide/ide-cd.c:1298:19: warning: cast to restricted __be32
drivers/ide/ide-cd.c:1300:4: warning: cast to restricted __be32
drivers/ide/ide-cd.c:1522:14: warning: cast to restricted __le16
drivers/ide/ide-cd.c:1523:14: warning: cast to restricted __le16
drivers/ide/ide-cd.c:1525:14: warning: cast to restricted __be16
drivers/ide/ide-cd.c:1526:14: warning: cast to restricted __be16
drivers/ide/ide-cd.c:1667:37: warning: cast to restricted __be16

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-off-by: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>