PCI: label: Fix compilation error when CONFIG_ACPI is unset

This patch fixes compilation error descibed below introduced by
the commit 6058989bad05b82e78baacce69ec14f27a11b5fd

drivers/pci/pci-label.c: In function ‘pci_create_firmware_label_files’:
drivers/pci/pci-label.c:366:2: error: implicit declaration of function ‘device_has_dsm’

Signed-off-by: Narendra K <narendra_k@dell.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
diff --git a/drivers/pci/pci-label.c b/drivers/pci/pci-label.c
index 824e247e..8c80138 100644
--- a/drivers/pci/pci-label.c
+++ b/drivers/pci/pci-label.c
@@ -174,6 +174,12 @@
 	return -1;
 }
 
+static inline bool
+device_has_dsm(struct device *dev)
+{
+	return false;
+}
+
 #else
 
 static const char device_label_dsm_uuid[] = {