soc/intel/tigerlake: Add chipset devicetree

Add aliases for devices and set most of them to off with the exception
of some essential devices.

Set a default register value as an example.

Change-Id: If50269808645ddc019e0d94fa8296df58ab7c367
Signed-off-by: Duncan Laurie <dlaurie@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/44038
Reviewed-by: Furquan Shaikh <furquan@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/intel/tigerlake/Kconfig

@@ -86,6 +86,10 @@ config FSP_TEMP_RAM_SIZE
 	  Refer to Platform FSP integration guide document to know
 	  the exact FSP requirement for Heap setup.
 
+config CHIPSET_DEVICETREE
+	string
+	default "soc/intel/tigerlake/chipset.cb"
+
 config IFD_CHIPSET
 	string
 	default "tgl"