tpm add default function definitions

Add default tpm_pcr_read/extend function definitions required
by IMA/Kconfig changes.
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Reviewed-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>

include/linux/tpm.h

@@ -31,5 +31,12 @@
 
 extern int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf);
 extern int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash);
+#else
+static inline int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf) {
+	return -ENODEV;
+}
+static inline int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash) {
+	return -ENODEV;
+}
 #endif
 #endif