As we don't execute the acpi_drv on Muen, we have to supply a static
'acpi' info as boot module. This is normally done by the
base/run/platform.inc include. However, when using base-hw-muen kernel
from a depot archive - as done by modern run scripts like
depot_download.run - the platform.inc magic is not applied.
This patch enhances the src archive of base-hw-muen with a mechanism
that creates a pre-defined acpi info at the bin directory via an
artificial src/acpi/target.mk file. This way, the static acpi ROM ends
up as boot module when importing the base-hw-muen archive into a
run script.
