In C, func() is a function taking an unspecified number of arguments,
vs func(void) a function taking no arguments. In C++ both forms indicate
"no arguments."
Update these headers to use the (void) form, which is correct in both
languages and avoids complaints when -Wstrict-prototypes is specified.
* fix #if in hardware/structs/dma.h
* move dma driver code from register definitions to dma drivers
Co-authored-by: Peter Lawrence <12226419+majbthrd@users.noreply.github.com>