[klibc] alpha: Fix definitions of _NSIG and struct sigaction

Origin: https://git.kernel.org/pub/scm/libs/klibc/klibc.git/commit/?id=1cd11aaed1dece773c6b1ce2e99a0fe98b51321e

We use the RT signals API, but include the kernel UAPI header
that defines _NSIG and struct sigaction for the old API.

Copy over all the definitions and fix those two.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Gbp-Pq: Name 0001-klibc-alpha-Fix-definitions-of-_NSIG-and-struct-siga.patch

klibc (2.0.8-6.1) unstable; urgency=medium

  * Non-maintainer upload.
  * {set,long}jmp [s390x]: save/restore the correct FPU registers
    (f8‥f15 not f1/f3/f5/f7) (Closes: #943425)

[dgit import unpatched klibc 2.0.8-6.1]

Import klibc_2.0.8-6.1.debian.tar.xz

[dgit import tarball klibc 2.0.8-6.1 klibc_2.0.8-6.1.debian.tar.xz]

Import klibc_2.0.8.orig.tar.xz

[dgit import orig klibc_2.0.8.orig.tar.xz]