sys-kernel/coreos-*: bump to 4.8.2

[crawford]

I'm not clear on the best way to update the defconfigs. I know that these configs are bad:

scripts/kconfig/conf  --olddefconfig Kconfig
.config:242:warning: symbol value 'm' invalid for CPU_FREQ_STAT
.config:802:warning: override: reassigning to symbol TCG_TPM
.config:803:warning: override: reassigning to symbol TCG_TIS
.config:880:warning: symbol value 'm' invalid for EXT4_ENCRYPTION
.config:943:warning: override: reassigning to symbol NET_9P_VIRTIO
.config:944:warning: override: reassigning to symbol NET_9P_RDMA

I'm worried that even if I fix CPU_FREQ_STAT and EXT4_ENCRYPTION there will still be other options that need to be updated.

[crawford]

Will fix coreos/bugs#1563.

[dm0-]

Assuming all those patch changes were reviewed, the overlay updates LGTM.