Bug#803159: linux: Enable DT support for armel/orion5x arch

[Roger Shimizu <rogershimizu@gmail.com>]

Dear Ian,

Thanks for your comments!

> Given this and the discussions
> https://lists.debian.org/debian-boot/2015/10/msg00221.html
> I wonder how useful it turns out to be to apply this patch.

1. This patch at least works well on jessie kernel (3.16).
2. I'm still trying to figure out why it doesn't work on sid kernel.
I thought it's because of the size, but currently I find it there may
be other reason. Because I tried to remove some kernel feature to let
the size go down below that limit, but it still cannot work.
I also tried to remove the same feature set for jessie kernel, and it
worked. So kernel size is not the root cause for my orion5x device.
3. The reason to support DT for my orion5x device (LS-WTGL) is because
there's no other way to support it. There were some patches to support
the device in legacy way, but it's not merged into mainline kernel, so
need to compile every time upstream get updated.
4. For LS-WSGL, sorry I don't have it. Debian previously support it,
but mainline kernel 4.3 has convert this device to DT, which means
legacy code has been removed and you have to use DT to boot. I notice
it's the same series product with my device, so I included it in my
patch.

I'm still working on "git bisect" for the sid kernel to try to find
out what's the root cause for my LS-WTGL device. It's not easy job
because there's debian kernel repo which manage the defconfig and
there's another linux repo separately which manage the code.
I hope you would not reject this patch immediately.
Thank you for your understanding!

Cheers,
Roger