payloads/coreinfo: Use correct integer types for loop indices

Make sure that the type of the loop index matches the type of the upper
bound. This fixes several -Wsign-compare warnings.

Change-Id: I73a88355d86288609e03f7a6fcaec14dfedac203
Signed-off-by: Jacob Garber <jgarber1@ualberta.ca>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/33863
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>

payloads/coreinfo/pci_module.c

@@ -51,7 +51,7 @@ static void swap(struct pci_devices *a, struct pci_devices *b)
 
 static int partition(struct pci_devices *list, int len)
 {
-	int val = list[len / 2].device;
+	pcidev_t val = list[len / 2].device;
 	int index = 0;
 	int i;