freezer: don't unnecessarily set PF_NOFREEZE explicitly

freezer: don't unnecessarily set PF_NOFREEZE explicitly

Some drivers set PF_NOFREEZE in their kthread functions which is
completely unnecessary and racy - some part of freezer code doesn't
consider cases where PF_NOFREEZE is set asynchronous to freezer
operations.

In general, there's no reason to allow setting PF_NOFREEZE explicitly.
Remove them and change the documentation to note that setting
PF_NOFREEZE directly isn't allowed.

-v2: Dropped change to twl4030-irq.c as it no longer uses PF_NOFREEZE.

Signed-off-by: Tejun Heo <[email protected]>
Acked-by: "Gustavo F. Padovan" <[email protected]>
Acked-by: Samuel Ortiz <[email protected]>
Cc: Marcel Holtmann <[email protected]>
Cc: wwang <[email protected]>