1.It make sense to let Toolchain.defs give the default value
2.The board can still change if the default isn't suitable
3.Avoid the same definition spread more than 200 Make.defs
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
Change-Id: Ic2649f1c7689bcf59c105ca8db61cad45b6e0e64
Remove support for the Codesourcery, Atollic, DevKitArm, Raisonance, and CodeRed toolchains. Not only are these tools old and no longer used but they are all equivalent to standard ARM EABI toolchains. Retaining specific support has no effect (they are still supported, but now just as generic EABI toolchains).
Mac OS X was renamed to macOS at some point. Update references to
OSX, OS X, Mac OS X, Mac OSX, and other permutations, to macOS,
in README files and in comments of other files.
