plat: xilinx: Move pm_client.h to common directory

Move pm_client.h to common directory to avoid duplication
of function declaration.

Signed-off-by: Tejas Patel <tejas.patel@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
Change-Id: Iea542e681f42db089cccd9b24d286ac8f0a2ce35
2 files changed