tpm: Fix compilation warning when CONFIG_PNP is not defined

The is_itpm() function is only accessed from a block surrounded by
#ifdef CONFIG_PNP. Therefore, also surround it with #ifdef CONFIG_PNP
and remove the #else branch causing the warning.

http://lxr.linux.no/#linux+v2.6.39/drivers/char/tpm/tpm_tis.c#L622

v2:
 - fixes a previous typo
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Reported-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: James Morris <jmorris@namei.org>

drivers/char/tpm/tpm_tis.c

@@ -80,7 +80,7 @@ enum tis_defaults {
 static LIST_HEAD(tis_chips);
 static DEFINE_SPINLOCK(tis_lock);
 
-#ifdef CONFIG_ACPI
+#ifdef CONFIG_PNP
 static int is_itpm(struct pnp_dev *dev)
 {
 	struct acpi_device *acpi = pnp_acpi_device(dev);
@@ -93,11 +93,6 @@ static int is_itpm(struct pnp_dev *dev)
 
 	return 0;
 }
-#else
-static int is_itpm(struct pnp_dev *dev)
-{
-	return 0;
-}
 #endif
 
 static int check_locality(struct tpm_chip *chip, int l)