nb/intel/pineview: Remove unused 'gpu_lvds_use_spread_spectrum_clock'

'gpu_lvds_use_spread_spectrum_clock'is only used on i945.

Change-Id: I0f63f18d3f57ef8774f22ca9eb8c20dd39c56cdc
Signed-off-by: Elyes Haouas <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/70147
Reviewed-by: Eric Lai <eric_lai@quanta.corp-partner.google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/northbridge/intel/pineview/chip.h

@@ -9,7 +9,6 @@ struct northbridge_intel_pineview_config {
 	/* GMA */
 	bool use_crt;
 	bool use_lvds;
-	int gpu_lvds_use_spread_spectrum_clock;
 	struct i915_gpu_controller_info gfx;
 };