zynqmp: pm: Update return type in query functions

zynqmp: pm: Update return type in query functions

In pm_query_data() function return type is stored in response so
there is no use of return type. Update return type of function
pm_query_data() from enum pm_ret_status to void. Similarly
update return type of pm_api_clock_get_name() and
pm_api_pinctrl_get_function_name() functions.

Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Change-Id: Id811926f0b4ebcc472480bb94f3b88109eb036cd