v21.02.0
imagebuilder: unset BINARY_FOLDER and DOWNLOAD_FOLDER in final archive
ath79: add support for onion omega
sdk: unset BINARY_FOLDER and DOWNLOAD_FOLDER in final archives
target: fix copying of licenses for SDK/toolchain
build: define PWM_SUPPORT arch feature flag
build: make <subdir>/install opt-in, use it for target/ only