ide: add ->tf_load and ->tf_read methods

* Add ->tf_load and ->tf_read methods to ide_hwif_t and set the default
  methods in default_hwif_transport().

* Use ->tf_{load,read} instead o calling ide_tf_{load,read}() directly.

* Make ide_tf_{load,read}() static.

There should be no functional changes caused by this patch.

Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/ide-taskfile.c b/drivers/ide/ide-taskfile.c
index 9ec3ecd..9a846a0 100644
--- a/drivers/ide/ide-taskfile.c
+++ b/drivers/ide/ide-taskfile.c
@@ -109,7 +109,7 @@
 
 	if ((task->tf_flags & IDE_TFLAG_DMA_PIO_FALLBACK) == 0) {
 		ide_tf_dump(drive->name, tf);
-		ide_tf_load(drive, task);
+		hwif->tf_load(drive, task);
 	}
 
 	switch (task->data_phase) {