Instead of every "simple" target having their own duplicate file with
all the section mappings, just provide a single, simple,
"cortex-m-generic.ld" that works with our startup code and any simple
rom/ram system. This also drops the pointless copying of files all over
the place. Using -L flags properly is sufficient, and the standard file
is now in the root of the library already.
Somewhat replaces some earlier work done by hg/lg, but much more
complete, so we kept it as is, because it's bringing in even more parts
after this.
Reviewed-by: Karl Palsson <karlp@tweak.net.au>
