staging: vt6655: replace typedef struct tagSTxDataHead_g with struct vnt_tx_datahead_g

Replace members
b, a, wDuration_b, wDuration_a, wTimeStampOff_b and wTimeStampOff_a
with
b, a, duration_b, duration_a, time_stamp_off_b and time_stamp_off_a

Using __le16 endian type for unsigned short.

Creating the new structure in rxtx.h

Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>