staging: comedi: addi_apci_3120: move timer 2 enable in apci3120_cyclic_ai()

Move the enable of timer 2 to avoid needing the extra if() check.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>