tpm: fix regression caused by section type conflict of tpm_dev_release() in ppc builds

The 81198078 commit reintroduced a regression
(error: __ksymtab_tpm_dev_release causes a section type conflict) that was fixed by commit
cbb2ed4a.
Fix it for good by adding the prototype to tpm.h so sparse doesn't
complain about it anymore.
Reported-by: NTony Camuso <tcamuso@redhat.com>
Signed-off-by: NPeter Huewe <peterhuewe@gmx.de>

drivers/char/tpm/tpm.c

@@ -1472,7 +1472,7 @@ EXPORT_SYMBOL_GPL(tpm_dev_vendor_release);
  * Once all references to platform device are down to 0,
  * release all allocated structures.
  */
-static void tpm_dev_release(struct device *dev)
+void tpm_dev_release(struct device *dev)
 {
 	struct tpm_chip *chip = dev_get_drvdata(dev);
 

drivers/char/tpm/tpm.h

@@ -332,6 +332,7 @@ extern struct tpm_chip* tpm_register_hardware(struct device *,
 				 const struct tpm_vendor_specific *);
 extern int tpm_open(struct inode *, struct file *);
 extern int tpm_release(struct inode *, struct file *);
+extern void tpm_dev_release(struct device *dev);
 extern void tpm_dev_vendor_release(struct tpm_chip *);
 extern ssize_t tpm_write(struct file *, const char __user *, size_t,
 			 loff_t *);