ACPI: Obsolete FADT duty_offset and duty_width fields

After the obsoletion of Processor() it is necessary to provide
_PTC package to define P_CNT IO address for clock throttling.
The platforms touched here already emit empty _PTC to disable
clock throttling.

Change-Id: I0e84c8ccd2772c9b3d61f71b74324c8d28f4eefe
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/74438
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/acpi/acpi.c b/src/acpi/acpi.c
index f8994eb..fb9a758 100644
--- a/src/acpi/acpi.c
+++ b/src/acpi/acpi.c
@@ -1689,6 +1689,10 @@
 	fadt->p_lvl2_lat = ACPI_FADT_C2_NOT_SUPPORTED;
 	fadt->p_lvl3_lat = ACPI_FADT_C3_NOT_SUPPORTED;
 
+	/* Use CPU _PTC instead to provide P_CNT details. */
+	fadt->duty_offset = 0;
+	fadt->duty_width = 0;
+
 	fadt->preferred_pm_profile = acpi_get_preferred_pm_profile();
 
 	if (CONFIG(USE_PC_CMOS_ALTCENTURY))