layer.conf: Make yocto 3.2 compatible
layer.conf: Make yocto 3.2 compatible

Drop old releaaes from LAYERSERIES_COMPAT if needed please use dunfell
branch

Signed-off-by: Khem Raj <729d64b6f67515e258459a5f6d20ec88b2caf8df@gmail.com>

kraj/meta-openwrt