mg_disk: use defines from <linux/ata.h>
mg_disk: use defines from <linux/ata.h>

While at it:
- remove MG_REG_HEAD_MUST_BE_ON define
- remove MG_REG_CTRL_INTR_ENABLE define
- remove MG_REG_HEAD_LBA_MODE define
- remove unused defines

Cc: unsik Kim <08ddbfb3896d7095c098ea1da85b48928df5ddbe@gmail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <248de9df611a028e5eceb9d893a2ed6c24c89ef4@gmail.com>
Signed-off-by: Tejun Heo <546b05909706652891a87f7bfe385ae147f61f91@kernel.org>
Signed-off-by: Jens Axboe <165ab144a3ccfd9429d5c6466b275f24fafdb114@oracle.com>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs