soc/intel/broadwell: Add int to unsigned

Fix the following issue detected by checkpatch:

WARNING: Prefer 'unsigned int' to bare use of 'unsigned'

TEST=None

Change-Id: Iae22e724b6adae16248db7dc8f822f65bfadae5f
Signed-off-by: Lee Leahy <Leroy.P.Leahy@intel.com>
Reviewed-on: https://review.coreboot.org/18873
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Philippe Mathieu-Daudé <philippe.mathieu.daude@gmail.com>

src/soc/intel/broadwell/chip.c

@@ -61,7 +61,8 @@ struct chip_operations soc_intel_broadwell_ops = {
 	.init       = &broadwell_init_pre_device,
 };
 
-static void pci_set_subsystem(device_t dev, unsigned vendor, unsigned device)
+static void pci_set_subsystem(device_t dev, unsigned int vendor,
+	unsigned int device)
 {
 	if (!vendor || !device)
 		pci_write_config32(dev, PCI_SUBSYSTEM_VENDOR_ID,