domainGenerator.py: more flexible arguments
domainGenerator.py: more flexible arguments

Allow optional arguments (initial settings, single domains, EDDs) to be passed
with an empty list of files.

This will make it a lot easier to write helper scripts.

Issue: GMINL-6770

Change-Id: I99527376b25d607616a3e73f6b62d556b79a90d2
Signed-off-by: David Wagner <60228a510f9a76940848fa2d29321fc4edfc2119@intel.com>
Reviewed-on: https://android.intel.com/336161
Reviewed-by: Martin, AdrienX <ee150f6b8e08822415daad32531830cb0e04ad68@intel.com>
Reviewed-by: Seketeli, ApeleteX <e33e31153c548dcc1fad4887409f5968198a8212@intel.com>
Reviewed-by: Lilja, Ola <a11125fbd47576b3095be852ba4a5b8a19d2705c@intel.com>

android-ia/hardware_intel_parameter-framework,android-ia/hardware_intel_parameter-framework,android-ia/hardware_intel_parameter-framework