The I2C interface was not being correctly locked down per port.  As such
this can lead to race conditions that can cause issues.  This patch cleans
up the handling to make certain we are not experiencing racy I2C access.
Signed-off-by: NEmil Tantilov <emil.s.tantilov@intel.com>
Tested-by: NStephen Ko <stephen.s.ko@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>