lib: tpm: Add command to flush resources

This patch adds a function to the TPM library, which allows U-Boot to
flush resources, e.g. keys, from the TPM.

Signed-off-by: Mario Six <mario.six@gdsys.cc>
Reviewed-by: Stefan Roese <sr@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/drivers/tpm/Kconfig b/drivers/tpm/Kconfig
index 7ab34ce..3490ee0 100644
--- a/drivers/tpm/Kconfig
+++ b/drivers/tpm/Kconfig
@@ -82,4 +82,10 @@
 	  to the device using the standard TPM Interface Specification (TIS)
 	  protocol
 
+config TPM_FLUSH_RESOURCES
+	bool "Enable TPM resource flushing support"
+	depends on TPM
+	help
+	  Enable support to flush specific resources (e.g. keys) from the TPM.
+	  The functionality is available via the 'tpm' command as well.
 endmenu