libunwind: Fix build with fstack-protector on musl

libunwind: Fix build with fstack-protector on musl

libunwind makery inserts -nostdlib during linking
which fails the build on musl when security flags are enabled
since it remove ssp from linking, so add them explicitly
to SECURITY_LDFLAGS

disable tests for musl targets, tests use obsolete
posix APIs e.g. getcontext

patchout x86_local_resume() on x86, gets a working
linunwind on x86, it seems that it wont work even
in glibc case but lets leave it as it is for glibc
and apply the patch only for musl

(From OE-Core rev: c8ac9d483f6e1cfca82dad8cf3e0745935e96214)

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>