soc/intel/quark: Fix uninitialized variable d_variant

Initialize the d_variant variable.

Found-by: CID 1353356 Uninitialized variable

TEST=Build and run on Galileo Gen2

Change-Id: I26fba4e77f91d53b6ff9028669aa0186d3174639
Signed-off-by: Lee Leahy <leroy.p.leahy@intel.com>
Reviewed-on: https://review.coreboot.org/14338
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>

src/soc/intel/quark/romstage/report_platform.c

@@ -86,6 +86,7 @@ static void report_cpu_info(void)
 		& B_ROM_FUSE_IN_SECURE_SKU));
 
 	/* TODO: Determine if this is a D variant */
+	d_variant = 0;
 	if (ecc_enabled && secure_boot)
 		d_variant = 0;	/* or 1 */