KEYS: Extend TIF_NOTIFY_RESUME to (almost) all architectures [try #6]

KEYS: Extend TIF_NOTIFY_RESUME to (almost) all architectures [try #6]

Implement TIF_NOTIFY_RESUME for most of those architectures in which isn't yet
available, and, whilst we're at it, have it call the appropriate tracehook.

After this patch, blackfin, m68k* and xtensa still lack support and need
alteration of assembly code to make it work.

Resume notification can then be used (by a later patch) to install a new
session keyring on the parent of a process.

Signed-off-by: David Howells <[email protected]>
Acked-by: Russell King <[email protected]>
cc: [email protected]
Signed-off-by: James Morris <[email protected]>