mb/google/octopus: Disable BT before S5 entry

The CNVi wifi/bt module prevents entry into S5 by keeping internal
SoC clocks running. Therefore it's necessary to disable BT prior to
S5 entry.

BUG=b:79606769
TEST= Test if BT device works under following cases:
1. Power-on
2. Press powerbtn before OS entry
3. Power-on from S5 again

Change-Id: Ibc14b4080a27de48d197e16d0eed162603482de2
Signed-off-by: Hannah Williams <hannah.williams@intel.com>
Reviewed-on: https://review.coreboot.org/26238
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
3 files changed