linux-user/elfload: Parse NT_GNU_PROPERTY_TYPE_0 notes

This is generic support, with the code disabled for all targets.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201021173749.111103-11-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>