1. return -1 if read voltage error before reporting battery's event;

1. return -1 if read voltage error before reporting battery's event;
2. change to use delay workqueue to wait spi resume;
3. delete flush(dws) operation from spi resume function to avoid spi error while system resume;
4. delete suspend_noirq function from wm831x_on.c to avoid reading spi before spim resume;
5. add touchscreen delay to 200us to avoid i2c error;