post_proc: send ENABLE_FLAG directly to offload effect driver

Enable flag should be sent directly through offload effect driver to
adsp whenever bundle receives EFFECT_CMD_ENABLE. Otherwise enablement
will only take effect in adsp after subsequent parameters being set, and
that's not expected.

Change-Id: I5a8f936095b5667f0e04b9109b67eaa0faec3a69
2 files changed