tomoyo: revert CONFIG_SECURITY_TOMOYO_LKM support

tomoyo: revert CONFIG_SECURITY_TOMOYO_LKM support

This patch reverts two TOMOYO patches that were merged into Linus' tree
during the v6.12 merge window:

8b985bbfabbe ("tomoyo: allow building as a loadable LSM module")
268225a1de1a ("tomoyo: preparation step for building as a loadable LSM module")

Together these two patches introduced the CONFIG_SECURITY_TOMOYO_LKM
Kconfig build option which enabled a TOMOYO specific dynamic LSM loading
mechanism (see the original commits for more details).  Unfortunately,
this approach was widely rejected by the LSM community as well as some
members of the general kernel community.  Objections included concerns
over setting a bad precedent regarding individual LSMs managing their
LSM callback registrations as well as general kernel symbol exporting
practices.  With little to no support for the CONFIG_SECURITY_TOMOYO_LKM
approach outside of Tetsuo, and multiple objections, we need to revert
these changes.

Link: https://lore.kernel.org/all/0c4b443a-9c72-4800-97e8-a3816b6a9ae2@I-love.SAKURA.ne.jp
Link: https://lore.kernel.org/all/CAHC9VhR=QjdoHG3wJgHFJkKYBg7vkQH2MpffgVzQ0tAByo_wRg@mail.gmail.com
Acked-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>