Only pulling out the _common_ stuff. This is a single step in a long
process of eliminating all the duplication and "same, but different"
implementations that are stalling adding nice clean easy support for
l0/f7/l4.
This _ignores_ all currently conflict register definitions, even if they
"do the same thing" it just pulls up the common stuff. A subsequent
commit can look at resolving the implementatations to a single version.
