ide: add generic ATA/ATAPI disk driver

* Add struct ide_disk_ops containing protocol specific methods.

* Add 'struct ide_disk_ops *' to ide_drive_t.

* Convert ide-{disk,floppy} drivers to use struct ide_disk_ops.

* Merge ide-{disk,floppy} drivers into generic ide-gd driver.

While at it:
- ide_disk_init_capacity() -> ide_disk_get_capacity()

Acked-by: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/ide-disk_ioctl.c b/drivers/ide/ide-disk_ioctl.c
index e6624ed..a49698b 100644
--- a/drivers/ide/ide-disk_ioctl.c
+++ b/drivers/ide/ide-disk_ioctl.c
@@ -13,12 +13,10 @@
 { 0 }
 };
 
-int ide_disk_ioctl(struct inode *inode, struct file *file,
+int ide_disk_ioctl(ide_drive_t *drive, struct inode *inode, struct file *file,
 		   unsigned int cmd, unsigned long arg)
 {
 	struct block_device *bdev = inode->i_bdev;
-	struct ide_disk_obj *idkp = ide_drv_g(bdev->bd_disk, ide_disk_obj);
-	ide_drive_t *drive = idkp->drive;
 	int err;
 
 	err = ide_setting_ioctl(drive, bdev, cmd, arg, ide_disk_ioctl_settings);