dgnc: use linux/types.h instead of dgnc_types.h

Dgnc_types.h unnecesarily defines TRUE as 1 and FALSE as 0 because we
already have a widely used linux/types.h so convert all TRUE to true,
FALSE to false and edit the dgnc_board struct to make sure it uses
"bool".

Signed-off-by: Giedrius Statkevičius <giedrius.statkevicius@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>