soc/intel: replace dt option PmTimerDisabled by Kconfig

Replace the dt option `PmTimerDisabled` with use of the Kconfig option
`USE_PM_ACPI_TIMER` for enabling/disabling the PM Timer.

A default value representing the prior devicetree value was added to the
boards system76/{lemp10,galp5,darp7}, so this change will not alter
behaviour.

Change-Id: If1811c6b98847b22272acfa35ca44f4fbca68947
Signed-off-by: Michael Niewöhner <foss@mniewoehner.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/58016
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Lance Zhao
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Reviewed-by: Tim Crawford <tcrawford@system76.com>
Reviewed-by: Nico Huber <nico.h@gmx.de>
diff --git a/src/soc/intel/alderlake/finalize.c b/src/soc/intel/alderlake/finalize.c
index c821e25..4ef572b 100644
--- a/src/soc/intel/alderlake/finalize.c
+++ b/src/soc/intel/alderlake/finalize.c
@@ -50,7 +50,7 @@
 
 static void pch_finalize(void)
 {
-	config_t *config;
+	config_t *config = config_of_soc();
 
 	/* TCO Lock down */
 	tco_lockdown();
@@ -58,13 +58,12 @@
 	/* TODO: Add Thermal Configuration */
 
 	/*
-	 * Disable ACPI PM timer based on dt policy
+	 * Disable ACPI PM timer based on Kconfig
 	 *
 	 * Disabling ACPI PM timer is necessary for XTAL OSC shutdown.
 	 * Disabling ACPI PM timer also switches off TCO
 	 */
-	config = config_of_soc();
-	if (config->PmTimerDisabled)
+	if (!CONFIG(USE_PM_ACPI_TIMER))
 		pmc_disable_acpi_timer();
 
 	pch_handle_sideband(config);