init: Allow appends to the property service permission structs

Extends device_perms.h API to allow property_perms and control_perms to be
appended on a device-specific basis, without needing to redefine the entire
struct contents.

Conflicts:
	init/property_service.c

Change-Id: Ifa4ec83cbd72b063da5bb8964677fcfd8f4831c5