ide: call {in|out}put_data() methods from tf_{read|load}() methods (take 2)

Handle IDE_FTFLAG_{IN|OUT}_DATA flags in tf_{read|load}() methods by calling
{in|out}put_data() methods to transfer 2 bytes -- this will allow us to move
that handling out of those methods altogether...

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>