The synchronization with the ACPI driver is not needed when starting
acpica at a later stage. It could already be disabled via the
'acpi_ready="yes"' config attribute. However, acpica still
unconditionally requests the so-called "Acpi" service, which is an
alias for the platform_drv's "Platform" service. This patch disables the
use of this alias when the 'acpi_ready' synchronization is disabled.
This patch adjusts the various users of the 'Child' API to the changes
on the account of the new non-blocking parent interface. It also removes
the use of the no-longer-available 'Connection::KEEP_OPEN' feature.
With the adjustment, we took the opportunity to redesign several
components to fit the non-blocking execution model much better, in
particular the demo applications.
Issue #2120
