cpu/$(CPU)/Makefile.features and cpu/$(CPU)/Makefile.dep are
automatically included
Part of moving CPU/CPU_MODEL definition to Makefile.features to have it
available before Makefile.include.
FLASHER and FFLAGS are evaluated by the main Makefile.include or by file
included by it. Their value does not need to be exported.
This will also prevent evaluating 'PORT' for FFLAGS when not needed.
Testing
-------
`git diff --word-diff` only reports `export` being removed.
`git show --stat` reports `84 insertions(+), 84 deletions(-)`
Which is the same amount as lines that where matching
`export[[:blank::]]\+VARIABLE`.
Get FLASH_FILE from command line instead of environment variable.
The documentation was claiming ELFFILE was given as a command line argument
already, but is was not.
This is the same change as with `openocd.sh`.
The board should process its CPU features.
This has the consequence to make 'periph_pm' visible to the board.
I also removed the duplicate FEATURES_PROVIDED from the board defined in
the cpu.
Remove duplicate handling of `periph_rtc` dependency to `periph_rtt` now
declared in the cpu.
Also the makefiles should not parse FEATURES_REQUIRED as it does not
guarantee anything as features could also be requested by FEATURES_OPTIONAL.
In practice it should parse it using `USEMODULE`.
Added HiFive1 to BOARD_INSUFFICIENT_MEMORY list for examples and tests that are too big to fit
build: fixed missing syscall and cpuid failures
Added missing syscall stubs for nanostubs and fixed compile error with cpuid periph
build: fixed whitespace error
build: add hifive1 to more BOARD_INSUFFICIENT_MEMORY
doc: fixed doxygen warnings
Addressed Doxygen warnings in source file comments
doc: more doxygen fixes
doc: even more doxygen fixes
doc: more changes
build: fix pedantic and rdci_simple build failures
make: exclude lua
