ch-release-v6.12.8-20250114

build: Store default configurations in tree

Create a new `ch_defconfig` file and use that instead of downloading the
kernel from the CH repository.

Signed-off-by: Rob Bradford <[email protected]>

ch-release-v6.2-20240908

github: Add binary kernel binary build and upload

Signed-off-by: Rob Bradford <[email protected]>