config: sandbox: enable qfw and cmd_qfw for testing

This patch enables qfw and cmd_qfw on sandbox for build coverage test

Signed-off-by: Miao Yan <yanmiaobest@gmail.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/configs/sandbox_defconfig b/configs/sandbox_defconfig
index aec2e53..9e4a92d 100644
--- a/configs/sandbox_defconfig
+++ b/configs/sandbox_defconfig
@@ -48,6 +48,7 @@
 CONFIG_CMD_TIME=y
 CONFIG_CMD_TIMER=y
 CONFIG_CMD_SOUND=y
+CONFIG_CMD_QFW=y
 CONFIG_CMD_BOOTSTAGE=y
 CONFIG_CMD_PMIC=y
 CONFIG_CMD_REGULATOR=y