sandbox: Enable dhry command

Provide access to the dhrystone benchmark command.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/sandbox_defconfig b/configs/sandbox_defconfig
index 598519d..7aea381 100644
--- a/configs/sandbox_defconfig
+++ b/configs/sandbox_defconfig
@@ -18,6 +18,7 @@
 CONFIG_SPI_FLASH=y
 CONFIG_SPI_FLASH_SANDBOX=y
 CONFIG_CMD_CROS_EC=y
+CONFIG_CMD_DHRYSTONE=y
 CONFIG_CROS_EC=y
 CONFIG_CROS_EC_SANDBOX=y
 CONFIG_DM_ETH=y