lib: tpm: Add command to list resources

It is sometimes convenient to know how many and/or which resources are
currently loaded into a TPG, e.g. to test is a flush operation succeeded.

Hence, we add a command that lists the resources of a given type currently
loaded into the TPM.

Signed-off-by: Mario Six <mario.six@gdsys.cc>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/tpm/Kconfig b/drivers/tpm/Kconfig
index a54b6a9..2a64bc4 100644
--- a/drivers/tpm/Kconfig
+++ b/drivers/tpm/Kconfig
@@ -96,4 +96,11 @@
 	  Enable support to load keys into the TPM by identifying
 	  their parent via the public key's SHA1 hash.
 	  The functionality is available via the 'tpm' command as well.
+
+config TPM_LIST_RESOURCES
+	bool "Enable TPM resource listing support"
+	depends on TPM
+	help
+	  Enable support to list specific resources (e.g. keys) within the TPM.
+	  The functionality is available via the 'tpm' command as well.
 endmenu