soc/intel/alderlake: Make use of is_devfn_enabled() function

1. Replace all pcidev_path_on_root() and is_dev_enabled() functions
combination with is_devfn_enabled().
2. Remove unused local variable of device structure type
(struct device *).
3. Replace pcidev_path_on_root() and dev->enabled check with
is_devfn_enabled() call.

TEST=Able to build and boot without any regression seen on ADL.

Change-Id: I92671992ec14fd2adca1635b0791ac8b456332e9
Signed-off-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/55292
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/soc/intel/alderlake/acpi.c b/src/soc/intel/alderlake/acpi.c
index 04d2a29..23d2a26 100644
--- a/src/soc/intel/alderlake/acpi.c
+++ b/src/soc/intel/alderlake/acpi.c
@@ -172,11 +172,10 @@
 
 static unsigned long soc_fill_dmar(unsigned long current)
 {
-	const struct device *const igfx_dev = pcidev_path_on_root(SA_DEVFN_IGD);
 	const uint64_t gfxvtbar = MCHBAR64(GFXVTBAR) & VTBAR_MASK;
 	const bool gfxvten = MCHBAR32(GFXVTBAR) & VTBAR_ENABLED;
 
-	if (is_dev_enabled(igfx_dev) && gfxvtbar && gfxvten) {
+	if (is_devfn_enabled(SA_DEVFN_IGD) && gfxvtbar && gfxvten) {
 		const unsigned long tmp = current;
 
 		current += acpi_create_dmar_drhd(current, 0, 0, gfxvtbar);
@@ -185,11 +184,10 @@
 		acpi_dmar_drhd_fixup(tmp, current);
 	}
 
-	const struct device *const ipu_dev = pcidev_path_on_root(SA_DEVFN_IPU);
 	const uint64_t ipuvtbar = MCHBAR64(IPUVTBAR) & VTBAR_MASK;
 	const bool ipuvten = MCHBAR32(IPUVTBAR) & VTBAR_ENABLED;
 
-	if (is_dev_enabled(ipu_dev) && ipuvtbar && ipuvten) {
+	if (is_devfn_enabled(SA_DEVFN_IPU) && ipuvtbar && ipuvten) {
 		const unsigned long tmp = current;
 
 		current += acpi_create_dmar_drhd(current, 0, 0, ipuvtbar);
@@ -200,8 +198,7 @@
 
 	/* TCSS Thunderbolt root ports */
 	for (unsigned int i = 0; i < MAX_TBT_PCIE_PORT; i++) {
-		const struct device *const tbt_dev = pcidev_path_on_root(SA_DEVFN_TBT(i));
-		if (is_dev_enabled(tbt_dev)) {
+		if (is_devfn_enabled(SA_DEVFN_TBT(i))) {
 			const uint64_t tbtbar = MCHBAR64(TBTxBAR(i)) & VTBAR_MASK;
 			const bool tbten = MCHBAR32(TBTxBAR(i)) & VTBAR_ENABLED;
 			if (tbtbar && tbten) {
@@ -235,7 +232,7 @@
 	}
 
 	/* Add RMRR entry */
-	if (is_dev_enabled(igfx_dev)) {
+	if (is_devfn_enabled(SA_DEVFN_IGD)) {
 		const unsigned long tmp = current;
 		current += acpi_create_dmar_rmrr(current, 0,
 				sa_get_gsm_base(), sa_get_tolud_base() - 1);