soc: xilinx: Fix race condition in event registration

In the Linux kernel, the following vulnerability has been resolved: soc: xilinx: Fix race condition in event registration The zynqmp_power driver registers handlers for suspend and subsystem restart events using register_event(). However, the work structures (zynqmp_pm_init_suspend_work and zynqmp_pm_init_restart_work) used by these handlers were allocated and initialized after the registration call. This created a race window where, if the firmware triggered an event immediately after registration but before allocation, the callback (suspend_event_callback or subsystem_restart_event_callback) would dereference a NULL pointer in work_pending(), leading to a crash. Fix this by allocating and initializing the work structures before registering the events.