MAINTAINERS: Add Xilinx Versal CPM Root Port maintainers

Add Bharat Kumar Gogada and Michal Simek as maintainers for driver and
documentation of Xilinx Versal CPM Root Port device.

Link: https://lore.kernel.org/r/20220618052022.10388-1-bharat.kumar.gogada@xilinx.com
Signed-off-by: Bharat Kumar Gogada <bharat.kumar.gogada@xilinx.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Michal Simek <michal.simek@amd.com>