dm: tpm: sandbox: Convert TPM driver to driver model

Convert the sandbox TPM driver to use driver model. Add it to the device
tree so that it can be found on start-up.

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/configs/sandbox_defconfig b/configs/sandbox_defconfig
index b68d688..2600bf7 100644
--- a/configs/sandbox_defconfig
+++ b/configs/sandbox_defconfig
@@ -31,6 +31,7 @@
 CONFIG_LED=y
 CONFIG_LED_GPIO=y
 CONFIG_SANDBOX_SERIAL=y
+CONFIG_DM_TPM=y
 CONFIG_TPM_TIS_SANDBOX=y
 CONFIG_SYS_I2C_SANDBOX=y
 CONFIG_SANDBOX_SPI=y