soc/intel/broadwell: Make broadwell_init_pre_device static

This small function is only used in one place.

Change-Id: Ieccdca60fb7837b6406a6b2fd7ebae86958a1afe
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/49945
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/intel/broadwell/northbridge.c

@@ -474,6 +474,11 @@ static void broadwell_enable(struct device *dev)
 	}
 }
 
+static void broadwell_init_pre_device(void *chip_info)
+{
+	broadwell_run_reference_code();
+}
+
 struct chip_operations soc_intel_broadwell_ops = {
 	CHIP_NAME("Intel Broadwell")
 	.enable_dev = &broadwell_enable,