i810: fix module_param bool abuse.

The driver says "module_param(ddc3, bool, 0);".  But it's not a used
as a bool, it's used as a count.

Make it a bool.

Cc: Antonino Daplas <adaplas@gmail.com>
Cc: linux-fbdev@vger.kernel.org
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>