configs/zynq_zed: linux: bump to latest mainline kernel

The Zynq SoCs are now well supported in the mainline kernel, thus stop
using the Xilinx fork.

As there is not xilinx_zynq defconfig in mainline, use the default
arch config.

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>