tpm: Add TPM2 support for read/write values

Implement this API function for TPM2.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
diff --git a/include/tpm-common.h b/include/tpm-common.h
index c1309a2..998b4fb 100644
--- a/include/tpm-common.h
+++ b/include/tpm-common.h
@@ -55,6 +55,8 @@
  * @buf:		Buffer used during the exchanges with the chip
  * @pcr_count:		Number of PCR per bank
  * @pcr_select_min:	Minimum size in bytes of the pcrSelect array
+ * @plat_hier_disabled:	Platform hierarchy has been disabled (TPM is locked
+ *			down until next reboot)
  */
 struct tpm_chip_priv {
 	enum tpm_version version;
@@ -66,6 +68,7 @@
 	/* TPM v2 specific data */
 	uint pcr_count;
 	uint pcr_select_min;
+	bool plat_hier_disabled;
 };
 
 /**