tpm: Add Kconfig options for TPMs

Add new Kconfig options for TPMs in preparation for moving boards to use
Kconfig for TPM configuration.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Christophe Ricard<christophe-h.ricard@st.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
diff --git a/lib/Kconfig b/lib/Kconfig
index 884218a..0673072 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -54,6 +54,16 @@
 
 source lib/rsa/Kconfig
 
+config TPM
+	bool "Trusted Platform Module (TPM) Support"
+	help
+	  This enables support for TPMs which can be used to provide security
+	  features for your board. The TPM can be connected via LPC or I2C
+	  and a sandbox TPM is provided for testing purposes. Use the 'tpm'
+	  command to interactive the TPM. Driver model support is provided
+	  for the low-level TPM interface, but only one TPM is supported at
+	  a time by the TPM library.
+
 menu "Hashing Support"
 
 config SHA1