acpi: Add SSDT pstate helper functions

Add new generic helper functions for PSS, PCT, XPSS, objects.

BUG=b:155307433
TEST=Boot Morphius and dump SSDT. Confirm PSS and PCT objects appear
as expected and conform to ACPI_6_3_May16.pdf ACPI specification.
Check XPSS against Microsoft "Extended PSS ACPI Method Specification"
XPSS_spec.doc April 2, 2007.
BRANCH=Zork

Change-Id: I1ea218bcee33093481e82390550ff96d9d2cb8b5
Signed-off-by: Jason Glenesk <jason.glenesk@amd.corp-partner.google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/45437
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Raul Rangel <rrangel@chromium.org>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
diff --git a/src/include/acpi/acpi.h b/src/include/acpi/acpi.h
index 58e1dbe..53308f3 100644
--- a/src/include/acpi/acpi.h
+++ b/src/include/acpi/acpi.h
@@ -800,6 +800,26 @@
 	acpi_addr_t resource;
 } __packed acpi_cstate_t;
 
+struct acpi_sw_pstate {
+	u32 core_freq;
+	u32 power;
+	u32 transition_latency;
+	u32 bus_master_latency;
+	u32 control_value;
+	u32 status_value;
+} __packed;
+
+struct acpi_xpss_sw_pstate {
+	u64 core_freq;
+	u64 power;
+	u64 transition_latency;
+	u64 bus_master_latency;
+	u64 control_value;
+	u64 status_value;
+	u64 control_mask;
+	u64 status_mask;
+} __packed;
+
 typedef struct acpi_tstate {
 	u32 percent;
 	u32 power;