Revert "driver core: Don't do deferred probe in parallel with kernel_init thread"

This reverts commit cec72f3e.

Commit cec72f3e ("driver core: Don't do deferred probe in parallel
with kernel_init thread") was fixing a commit 716a7a25

 ("driver
core: fw_devlink: Add support for batching fwnode parsing"). Since the
commit being fixed itself is going to be reverted, the fix can also be
reverted.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20201121020232.908850-4-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>