ide: add "flagged" taskfile flags to struct ide_taskfile (v2)

* Add ->ftf_flags field to struct ide_taskfile
  and convert flags for TASKFILE ioctl to use it.

* Rename "flagged" taskfile flags:
  - IDE_TFLAG_FLAGGED -> IDE_FTFLAG_FLAGGED
  - IDE_TFLAG_FLAGGED_SET_IN_FLAGS -> IDE_FTFLAG_SET_IN_FLAGS
  - IDE_TFLAG_{OUT,IN}_DATA -> IDE_FTFLAG_{OUT,IN}_DATA

v2:
* Remember to fully update ide-h8300.c, scc_pata.c and tx493{8,9}ide.c
  (thanks to Stephen Rothwell for noticing).

There should be no functional changes caused by this patch.

Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>