linux-xlnx: Add recipe for v3.19 Xilinx kernel
linux-xlnx: Add recipe for v3.19 Xilinx kernel

* Pin a commit from the master branch for a 3.19 based linux-xlnx kernel

Signed-off-by: Nathan Rossi <e1e6d173c6873c0ae2b831215d22380d293bb314@xilinx.com>

Xilinx/meta-xilinx,Xilinx/meta-xilinx,nathanrossi/meta-xilinx,Xilinx/meta-xilinx,nathanrossi/meta-xilinx,Xilinx/meta-xilinx,Xilinx/meta-xilinx,nathanrossi/meta-xilinx,Xilinx/meta-xilinx,nathanrossi/meta-xilinx