staging: vt6656: remove unused vnt_get_current_tsf() function

The function vnt_get_current_tsf() is not used anywhere, remove it.

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20230317064800.12276-1-straube.linux@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>