soc: xilinx: zynqmp: fix out of bounds array access

The call to xilinx_pm_request requires an array of a larger size.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Link: https://lore.kernel.org/r/5f1409de285d7454af171a54e5f115da9d82c44e.1650440343.git.michal.simek@xilinx.com