nb/intel/sandybridge: Add a chipset devicetree

This only moves CPU configuration to a common place. Other PCI devices
can be done in follow-ups.

Change-Id: I9c5b6f25b779e28b6719cf70455ff0f1a916ad87
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/56912
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/northbridge/intel/sandybridge/Kconfig b/src/northbridge/intel/sandybridge/Kconfig
index 551714a..bbe8ac4 100644
--- a/src/northbridge/intel/sandybridge/Kconfig
+++ b/src/northbridge/intel/sandybridge/Kconfig
@@ -17,6 +17,9 @@
 	select NO_DDR2
 	select USE_DDR3
 
+config CHIPSET_DEVICETREE
+	default "northbridge/intel/sandybridge/chipset.cb"
+
 config SANDYBRIDGE_VBOOT_IN_ROMSTAGE
 	bool
 	default n