xilinx: Move ipi configuration structure definition to header file

Move ipi configuration structure definition to common header file
and rename it to common name, so it can be used for Xilinx specific
other platforms in upcoming changes.

Signed-off-by: Tejas Patel <tejas.patel@xilinx.com>
Reviewed-by: Siva Durga Prasad Paladugu <siva.durga.paladugu@xilinx.com>
Signed-off-by: Jolly Shah <jollys@xilinx.com>