sb/intel/i82801ix: drop IGD-related NVS variables

NDID/DID entries are no longer used by the GMA SSDT generator, so
drop them. SSDT generation will be simplified in a subsequent commit.

Remove direct setting of gnvs->ndid in qemu-q35 board since build
will otherwise break.

Change-Id: Ifbf08f43291c1fff7ccbc85272dc97334207983b
Signed-off-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/39954
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/emulation/qemu-q35/acpi_tables.c

@@ -33,9 +33,6 @@ void acpi_create_gnvs(global_nvs_t *gnvs)
 	/* Enable both COM ports */
 	gnvs->cmap = 0x01;
 	gnvs->cmbp = 0x01;
-
-	/* IGD Displays */
-	gnvs->ndid = 0; /* Will use default of 0x00000400. */
 }