FROMLIST: refactor header includes to allow kthread.h inclusion in psi_types.h

kthread.h can't be included in psi_types.h because it creates a circular
inclusion with kthread.h eventually including psi_types.h and complaining
on kthread structures not being defined because they are defined further
in the kthread.h. Resolve this by removing psi_types.h inclusion from the
headers included from kthread.h.

Signed-off-by: Suren Baghdasaryan <surenb@google.com>

(not upstream yet, latest version published at: https://lore.kernel.org/patchwork/patch/1052417/

)

Conflicts:
        include/linux/kthread.h
        kernel/kthread.c

(1. <linux/cgroup.h> include is already missing in kthread.h
2. <linux/cgroup.h> is already included in kthread.c)

Bug: 127712811
Bug: 129157727
Test: lmkd in PSI mode
Change-Id: I07c1f4fddf0c43b3095f505e062d9d179d041544
Signed-off-by: Suren Baghdasaryan <surenb@google.com>