Lenovo E41-20 needs more time than 100ms to read VPC,
the funtion keys always failed responding.
Increase timeout to get the value from VPC, then
the funtion keys like mic mute key work well.
Signed-off-by: NAaron Ma <aaron.ma@canonical.com>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>