UPSTREAM: cfi: Add CFI_NOSEAL()

Add a CFI_NOSEAL() helper to mark functions that need to retain their
CFI information, despite not otherwise leaking their address.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20231215092707.669401084@infradead.org


Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Bug: 452811419
Change-Id: Id07aec59b57aa4443824bd3bc4f83eed9e8cc3e1
(cherry picked from commit e9d13b9d)
Signed-off-by: wei li <sirius.liwei@honor.corp-partner.google.com>