tpm: st33zp24: Add tpm st33zp24 spi support

Add support for TPM ST33ZP24 spi.

The ST33ZP24 does have a spi interface.
The transport protocol is proprietary.

For spi we are relying only on DM_SPI.

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
diff --git a/drivers/tpm/Kconfig b/drivers/tpm/Kconfig
index 9432160..9a7b7f5 100644
--- a/drivers/tpm/Kconfig
+++ b/drivers/tpm/Kconfig
@@ -73,4 +73,13 @@
 	  to the device using the standard TPM Interface Specification (TIS)
 	  protocol
 
+config TPM_ST33ZP24_SPI
+	bool "STMicroelectronics ST33ZP24 SPI TPM"
+	depends on TPM && DM_SPI
+	---help---
+	  This driver supports STMicroelectronics TPM devices connected on the SPI bus.
+	  The usual tpm operations and the 'tpm' command can be used to talk
+	  to the device using the standard TPM Interface Specification (TIS)
+	  protocol
+
 endmenu