configs: sandbox: Enable composite clk

Enable composite clk for sandbox test

Signed-off-by: Peng Fan <peng.fan@nxp.com>
diff --git a/configs/sandbox_flattree_defconfig b/configs/sandbox_flattree_defconfig
index 2429ae4..610457e 100644
--- a/configs/sandbox_flattree_defconfig
+++ b/configs/sandbox_flattree_defconfig
@@ -66,6 +66,7 @@
 CONFIG_ADC=y
 CONFIG_ADC_SANDBOX=y
 CONFIG_CLK=y
+CONFIG_CLK_COMPOSITE_CCF=y
 CONFIG_SANDBOX_CLK_CCF=y
 CONFIG_CPU=y
 CONFIG_DM_DEMO=y