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: NMiao Yan <yanmiaobest@gmail.com>
Reviewed-by: NBin Meng <bmeng.cn@gmail.com>

configs/sandbox_defconfig

@@ -48,6 +48,7 @@ CONFIG_CMD_LINK_LOCAL=y
 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