Revert "drivercore: Avoid adding devices without pm_ops to dpm list"

This reverts commit d36bb308.

Not able to add device with PM core and causing suspend/resume
issue in I2C client driver.pm_ops are removed from I2C bus type
and should fall back on client driver pm_ops.

Reverting this change as we are not able to register I2C
client devices with PM core.

Change-Id: I973a03b7cd0afca2edb584539ea5c69198bfb089
Signed-off-by: Gaurav Singhal <gsinghal@codeaurora.org>