* Remove SPEC declarations from mk/spec
* Remove all board-specific REQUIRE declaratiions left
* Replace [have_spec <board>] run-script declarations with have_board where necessary
* Remove addition of BOARD variable to SPECS in toplevel Makefile
* Move board-specific directories in base-hw out of specs
- Update FatFS port from 0.07e to 0.13
- Multi-device support
- Basic test at run/fatfs
- Adaption of existing components
Note, ffat is now consistently renamed to fatfs.
Ref #2410