sb/intel/i82371eb: Constify pci_devfn_t devices

Change-Id: I9056464b36cde89d2fe88ff27531e467297bed0b
Signed-off-by: Elyes Haouas <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/61986
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
diff --git a/src/southbridge/intel/i82371eb/early_smbus.c b/src/southbridge/intel/i82371eb/early_smbus.c
index 97cf5fd..1d08045 100644
--- a/src/southbridge/intel/i82371eb/early_smbus.c
+++ b/src/southbridge/intel/i82371eb/early_smbus.c
@@ -21,12 +21,11 @@
 
 int smbus_enable_iobar(uintptr_t base)
 {
-	pci_devfn_t dev;
 	u8 reg8;
 	u16 reg16;
 
 	/* Get the SMBus/PM device of the 82371AB/EB/MB. */
-	dev = pci_locate_device(PCI_ID(PCI_VENDOR_ID_INTEL,
+	const pci_devfn_t dev = pci_locate_device(PCI_ID(PCI_VENDOR_ID_INTEL,
 				PCI_DEVICE_ID_INTEL_82371AB_SMB_ACPI), 0);
 
 	/* Set the SMBus I/O base. */