zynqmp: pm: Correct function header of clock APIs
zynqmp: pm: Correct function header of clock APIs

Correct function header of pm_api_clock_getparent() and
pm_api_clock_setparent().

Signed-off-by: Rajan Vaja <958387e48e282671f29716c1b482329c5293cdb8@xilinx.com>
Acked-by: Will Wong <10380809987a76aa76a57175ed9a60befbe0e162@xilinx.com>

achingupta/arm-trusted-firmware,achingupta/arm-trusted-firmware