soc/intel/*/chip: Remove unused devicetree entry

InternalGfx isn't used so drop it.

Change-Id: I12f424d8d883e065ef8d007e56a8bff41a7fae53
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/47176
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

src/soc/intel/elkhartlake/chip.h

@@ -140,7 +140,6 @@ struct soc_intel_elkhartlake_config {
 
 	/* Gfx related */
 	uint8_t IgdDvmt50PreAlloc;
-	uint8_t InternalGfx;
 	uint8_t SkipExtGfxScan;
 
 	uint32_t GraphicsConfigPtr;