[meta-xilinx] meta-xilinx: Updated Kernels

[Nathan Rossi]

Hi All,

So as linux-yocto added recipes for the 4.1 kernel into oe-core
recently I have gone and updated the kernels in meta-xilinx. (in
master)

* Added linux-yocto 4.1 appends for MicroBlaze, Zynq and ZynqMP
* Added ZynqMP support for linux-yocto-dev
* Pinned linux-xlnx 3.19 recipe to the xilinx v2015.2 tag
* Updated the linux-xlnx-dev default branch and SRCREV

It would be great if anyone has a chance to test and report any issues
with any of these kernels.

I know there was some issues with the 4.1 kernel on MicroBlaze a
little while back. I haven't been able to reproduce those issues.
There is however a compilation bug for gcc 5.2 and microblaze big
endian (when compiling the kernel) which I need to investigate.

Also since QEMU was updated to 2.4.0 rc's I have removed the ZynqMP
specific QEMU. However it is important to note there is some
discrepancies between the device tree generated by mainline kernels
and the device tree that is generated by the linux-zynqmp-mainline
kernel (which works in QEMU).

Regards,
Nathan