staging: comedi: cb_pcidas: remove forward declarations 8

Move the trimpot_{7376,8402}_write functions to remove the need
for the forward declarations.

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