staging: comedi: dt3000: rename dual-ported RAM location defines

Rename these CamelCase defines and fix the checkpatch.pl issues:

CHECK: Avoid CamelCase: <DPR_{various}>
CHECK: spaces preferred around that '*' (ctx:VxV)
CHECK: spaces preferred around that '+' (ctx:VxV)

For aesthetics, move the defines to after the includes.

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>