tpm_tis: fix build when ACPI is not enabled

Fix tpm_tis.c build when CONFIG_ACPI is not enabled by providing a stub
function.  Fixes many build errors/warnings:

  drivers/char/tpm/tpm_tis.c:89: error: dereferencing pointer to incomplete type
  drivers/char/tpm/tpm_tis.c:89: warning: type defaults to 'int' in declaration of 'type name'
  drivers/char/tpm/tpm_tis.c:89: error: request for member 'list' in something not a structure or union
  ...
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Cc: Leendert van Doorn <leendert@watson.ibm.com>
Cc: James Morris <jmorris@namei.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.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_PNP
+#if defined(CONFIG_PNP) && defined(CONFIG_ACPI)
 static int is_itpm(struct pnp_dev *dev)
 {
 	struct acpi_device *acpi = pnp_acpi_device(dev);
@@ -93,6 +93,11 @@ static int is_itpm(struct pnp_dev *dev)
 
 	return 0;
 }
+#else
+static inline int is_itpm(struct pnp_dev *dev)
+{
+	return 0;
+}
 #endif
 
 static int check_locality(struct tpm_chip *chip, int l)