linux-yocto/5.15: powerpc: Fix reschedule bug in KUAP-unlocked user copy

Integrating the following commit(s) to linux-yocto/5.15:

    f100c753aa1f powerpc: Fix reschedule bug in KUAP-unlocked user copy

Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit b457e697)
Signed-off-by: Steve Sakoman <steve@sakoman.com>