dptf: Fix scope of TCPU device

In the initial DPTF refactor, the scope of the TCPU device was
incorrectly set as \_SB, instead of \_SB.PCI0. However, because of the
way that the acpi_inject_dsdt() callback currently works (it injects
contents before the dsdt.aml file), the Scope where the TCPU
device lives (\_SB.PCI0) doesn't exist yet. Therefore, to avoid playing
games with *when* things are defined in the DSDT, switch to defining all
of the DPTF devices in the SSDT.

Signed-off-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Change-Id: Ia4922b4dc6544d79d44d39e6ad18c6ab9fee0fd7
Reviewed-on: https://review.coreboot.org/c/coreboot/+/43529
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-by: Karthik Ramasubramanian <kramasub@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/include/acpi/acpigen_dptf.h

@@ -9,6 +9,10 @@
 /* A common idiom is to use a default value if none is provided (i.e., == 0) */
 #define DEFAULT_IF_0(thing, default_) ((thing) ? (thing) : (default_))
 
+/* Hardcoded paths */
+#define DPTF_DEVICE_PATH	"\\_SB.DPTF"
+#define TCPU_SCOPE		"\\_SB.PCI0"
+
 /* List of available participants (i.e., they can participate in policies) */
 enum dptf_participant {
 	DPTF_NONE,