asm-generic: siginfo: remove obsolete #ifdefs

The frv, tile and blackfin architectures are being removed, so
we can clean up this header by removing all the special cases
except those for ia64.

The SEGV_BNDERR and BUS_MCEERR_AR si_code macros are now
defined unconditionally on all remaining architectures.

Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>