soc/intel/{skl,cnl}: replace PM ACPI timer dt option by Kconfig

Select `PM_ACPI_TIMER_OPTIONAL` to enable the new PM ACPI Kconfig and
set the FSP option for PM ACPI timer enablement from its value instead
of using the old devicetree option.

Also drop the obsolete devicetree option from soc code and from the
mainboards and add a corresponding Kconfig entry instead.

Change-Id: I10724ccf1647594404cec15c2349ab05b6c9714f
Signed-off-by: Michael Niewöhner <foss@mniewoehner.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/45955
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/intel/skylake/chip.c

@@ -235,6 +235,8 @@ void platform_fsp_silicon_init_params_cb(FSPS_UPD *supd)
 	/* Legacy 8254 timer support */
 	params->Early8254ClockGatingEnable = !CONFIG(USE_LEGACY_8254_TIMER);
 
+	params->EnableTcoTimer = CONFIG(USE_PM_ACPI_TIMER);
+
 	memcpy(params->SerialIoDevMode, config->SerialIoDevMode,
 	       sizeof(params->SerialIoDevMode));
 
@@ -297,7 +299,6 @@ void platform_fsp_silicon_init_params_cb(FSPS_UPD *supd)
 	params->Device4Enable = dev && dev->enabled;
 	dev = pcidev_path_on_root(PCH_DEVFN_THERMAL);
 	params->PchThermalDeviceEnable = dev && dev->enabled;
-	params->EnableTcoTimer = !config->PmTimerDisabled;
 
 	tconfig->PchLockDownGlobalSmi = config->LockDownConfigGlobalSmi;
 	tconfig->PchLockDownRtcLock = config->LockDownConfigRtcLock;