igd.asl rewrite

Old igd.asl had inconsistent addresses (between _DOD and actual device)
and ghost devices. Any of those is enough to make brightness on windows
fail and make igd.asl out-of-ACPI-spec. Also old code favoured ridiculous
copying of the same thing 6 times per chipset. Leave only hooking up and
chipset-specific part in chipset directory. Move NVS handling and ACPI-spec
parts to a common file.

Change-Id: I556769e5e28b83e7465e3db689e26c8c0ab44757
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-on: http://review.coreboot.org/7472
Tested-by: build bot (Jenkins)
Reviewed-by: Edward O'Callaghan <edward.ocallaghan@koparo.com>
Reviewed-by: Timothy Pearson <tpearson@raptorengineeringinc.com>
diff --git a/src/northbridge/intel/i945/Kconfig b/src/northbridge/intel/i945/Kconfig
index a592666..b17dda6 100644
--- a/src/northbridge/intel/i945/Kconfig
+++ b/src/northbridge/intel/i945/Kconfig
@@ -29,6 +29,7 @@
 	select HAVE_DEBUG_RAM_SETUP
 	select LAPIC_MONOTONIC_TIMER
 	select VGA
+	select INTEL_GMA_ACPI
 
 config NORTHBRIDGE_INTEL_SUBTYPE_I945GC
 	def_bool n