soc/intel/xeon_sp: Clean up device enablement configuration

Clean up by using is_devfn_enabled().

Change-Id: I9ea3d8b1b18e84a75a81a7e926d2c638766bb493
Signed-off-by: Felix Singer <felixsinger@posteo.net>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/82120
Reviewed-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-by: Shuo Liu <shuo.liu@intel.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/soc/intel/xeon_sp/cpx/romstage.c b/src/soc/intel/xeon_sp/cpx/romstage.c
index fe2ca86..b72417e 100644
--- a/src/soc/intel/xeon_sp/cpx/romstage.c
+++ b/src/soc/intel/xeon_sp/cpx/romstage.c
@@ -123,7 +123,6 @@
 void platform_fsp_memory_init_params_cb(FSPM_UPD *mupd, uint32_t version)
 {
 	FSP_M_CONFIG *m_cfg = &mupd->FspmConfig;
-	const struct device *dev;
 	const config_t *config = config_of_soc();
 
 	/* ErrorLevel - 0 (disable) to 8 (verbose) */
@@ -175,8 +174,7 @@
 
 	/* Enable PCH thermal device in FSP, the definition of ThermalDeviceEnable is
 	   0: Disable, 1: Enabled in PCI mode, 2: Enabled in ACPI mode */
-	dev = pcidev_path_on_root(PCH_DEVFN_THERMAL);
-	m_cfg->ThermalDeviceEnable = dev && dev->enabled;
+	m_cfg->ThermalDeviceEnable = is_devfn_enabled(PCH_DEVFN_THERMAL);
 
 	/* Enable VT-d according to DTB */
 	m_cfg->VtdSupport = config->vtd_support;