tegra: nyan-big: Enable the dhrystone benchmark

Enable this so we can roughly measure CPU performance. Also enable the
cache command to allow for timing.

Signed-off-by: Simon Glass <sjg@chromium.org>

configs/nyan-big_defconfig

@@ -23,6 +23,7 @@ CONFIG_CMD_GPIO=y
 # CONFIG_CMD_SETEXPR is not set
 # CONFIG_CMD_NFS is not set
 CONFIG_CMD_BMP=y
+CONFIG_CMD_CACHE=y
 CONFIG_CMD_PMIC=y
 CONFIG_CMD_REGULATOR=y
 CONFIG_CMD_TPM=y
@@ -62,5 +63,6 @@ CONFIG_DM_VIDEO=y
 CONFIG_DISPLAY=y
 CONFIG_VIDEO_TEGRA124=y
 CONFIG_VIDEO_BRIDGE=y
+CONFIG_CMD_DHRYSTONE=y
 CONFIG_TPM=y
 CONFIG_ERRNO_STR=y