soc/braswell: Add CPUID for D0 stepping

Original-Reviewed-on: https://chromium-review.googlesource.com/309122
Original-Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
Original-Tested-by: Hannah Williams <hannah.williams@intel.com>

Change-Id: Ia24dbeb6b23ccbbb380843a4684def578cde168a
Signed-off-by: Divya Sasidharan <divya.s.sasidharan@intel.com>
Reviewed-on: https://review.coreboot.org/12727
Tested-by: build bot (Jenkins)
Reviewed-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Reviewed-by: Martin Roth <martinroth@google.com>

src/soc/intel/braswell/cpu.c

@@ -149,6 +149,7 @@ static struct device_operations cpu_dev_ops = {
 };
 
 static struct cpu_device_id cpu_table[] = {
+	{ X86_VENDOR_INTEL, 0x406C4 },
 	{ X86_VENDOR_INTEL, 0x406C3 },
 	{ X86_VENDOR_INTEL, 0x406C2 },
 	{ 0, 0 },