docs(maintainers): update xilinx record to cover docs

Recently new Xilinx Versal NET platform has been merged but documentation
cover only zynqmp. Fix the fragment to cover all Xilinx documentation.

Signed-off-by: Michal Simek <michal.simek@amd.com>
Change-Id: I10f8f865ca8d46518135adb80ba0ba4470534529
1 file changed