arm64: copy conditional instruction tests from arm

Copy the code that is used to compute if a conditional instruction
would be executed.

This code is needed to support A32 instruction emulation in the
kernel.

Change-Id: I0bab7537efd8cc317bd20995cd36961cf95165aa
Signed-off-by: Alex Van Brunt <avanbrunt@nvidia.com>
Reviewed-on: http://git-master/r/362154
Reviewed-on: http://git-master/r/365061


Reviewed-by: Richard Wiley <rwiley@nvidia.com>
Tested-by: Oskari Jaaskelainen <oskarij@nvidia.com>
Git-commit: 679b362a6fc9c5eb944042ddc700a0d093a12342
Git-repo: https://android.googlesource.com/kernel/tegra


[stepanm@codeaurora.org: resolve merge conflicts]
Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>