toolchain: gcc: improve patch handling by introducing major version

toolchain: gcc: improve patch handling by introducing major version

Every minor version bump of a major version will result in a huge patch
diff because of the moving of all the patches from version e.g. 11.2.0 to
11.3.0. This commit only use the major version for the patch folders to
differentiate between the different gcc versions. This will significantly
improve the reviewing of the smaller version bump patches and help to see
what really changed in a minor version bump.

Signed-off-by: Nick Hainke <vincent@systemli.org>