Remove unused power mode code stack::acl

  uint8_t sca; /* Sleep clock accuracy */

  void Reset();

  struct tPolicy {

    tBTM_PM_MODE Mode() const { return this->mode.mode_; }

    struct {

      bool IsPending() const { return pending_ != BTM_PM_MD_UNKNOWN; }

      tBTM_PM_MODE Pending() const { return pending_; }

      uint16_t Interval() const { return interval_; }

     private:

      tBTM_PM_MODE mode_{BTM_PM_MD_ACTIVE};

      tBTM_PM_MODE pending_{BTM_PM_MD_UNKNOWN};

      uint16_t interval_{0};

      friend tBTM_STATUS bluetooth::shim::BTM_SetPowerMode(

          uint16_t, const tBTM_PM_PWR_MD& new_mode);

      friend void bluetooth::shim::btm_pm_on_mode_change(tHCI_STATUS status,

                                                         uint16_t handle,

                                                         tHCI_MODE hci_mode,

                                                         uint16_t interval);

      friend void tACL_CONN::Reset();

      friend tBTM_PM_MODE tACL_CONN::tPolicy::Mode() const;

    } mode;

    hci_role_t Role() const { return this->role.role_; }

    struct {

      unsigned RoleSwitchFailedCount() const { return role_switch_failed_cnt_; }

     private:

      hci_role_t role_{HCI_ROLE_CENTRAL};

      unsigned role_switch_failed_cnt_{0};

      friend void tACL_CONN::Reset();

      friend hci_role_t tACL_CONN::tPolicy::Role() const;

    } role;

    struct {

      bool IsPending() const { return pending_; }

     private:

      bool pending_{false};

      friend tBTM_STATUS bluetooth::shim::BTM_SetSsrParams(uint16_t handle,

                                                           uint16_t max_lat,

                                                           uint16_t min_rmt_to,

                                                           uint16_t min_loc_to);

      friend void bluetooth::shim::btm_pm_on_sniff_subrating(

          tHCI_STATUS status, uint16_t handle,

          uint16_t maximum_transmit_latency, uint16_t maximum_receive_latency,

          uint16_t minimum_remote_timeout, uint16_t minimum_local_timeout);

      friend void tACL_CONN::Reset();

    } sniff_subrating;

    tLINK_POLICY Settings() const { return settings_; }

   private:

    tLINK_POLICY settings_{kAllLinkPoliciesEnabled};

    friend void btm_set_link_policy(tACL_CONN* conn, tLINK_POLICY policy);

    friend void tACL_CONN::Reset();

  } policy;

};

struct controller_t;