drivers: soc: xilinx: add the missing kfree in xlnx_add_cb_for_suspend()

In the Linux kernel, the following vulnerability has been resolved: drivers: soc: xilinx: add the missing kfree in xlnx_add_cb_for_suspend() If we fail to allocate memory for cb_data by kmalloc, the memory allocation for eve_data is never freed, add the missing kfree() in the error handling path.