mb/intel/adlrvp: Switch to using device pointers

This change replaces the device tree walks with device pointers by
using alias for dptf_policy device.

Change-Id: I02ca63ac2cc1b8ed2f5a381b3824c9beff7f33ec
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/57870
Reviewed-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/mainboard/intel/adlrvp/devicetree.cb b/src/mainboard/intel/adlrvp/devicetree.cb
index a19d1a3..cd198d5 100644
--- a/src/mainboard/intel/adlrvp/devicetree.cb
+++ b/src/mainboard/intel/adlrvp/devicetree.cb
@@ -307,7 +307,7 @@
 				register "options.fan.fine_grained_control" = "1"
 				register "options.fan.step_size" = "2"
 
-				device generic 0 on end
+				device generic 0 alias dptf_policy on end
 			end
 		end
 		device ref ipu on
diff --git a/src/mainboard/intel/adlrvp/ramstage.c b/src/mainboard/intel/adlrvp/ramstage.c
index 0e1f573..0c00d95 100644
--- a/src/mainboard/intel/adlrvp/ramstage.c
+++ b/src/mainboard/intel/adlrvp/ramstage.c
@@ -19,19 +19,14 @@
 	{ PCI_DEVICE_ID_INTEL_ADL_P_ID_3, 5000, 45000, 115000, 115000 },
 };
 
+WEAK_DEV_PTR(dptf_policy);
 void variant_update_power_limits(void)
 {
-	const struct device_path policy_path[] = {
-		{ .type = DEVICE_PATH_PCI, .pci.devfn = SA_DEVFN_DPTF},
-		{ .type = DEVICE_PATH_GENERIC, .generic.id = 0}
-	};
-
-	const struct device *policy_dev = find_dev_nested_path(pci_root_bus(),
-							policy_path, ARRAY_SIZE(policy_path));
+	const struct device *policy_dev = DEV_PTR(dptf_policy);
 	if (!policy_dev)
 		return;
 
-	struct drivers_intel_dptf_config *config = policy_dev->chip_info;
+	struct drivers_intel_dptf_config *config = config_of(policy_dev);
 
 	uint16_t mchid = pci_s_read_config16(PCI_DEV(0, 0, 0), PCI_DEVICE_ID);