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

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.

Fixes: 05e5ba40ea7a ("driver: soc: xilinx: Add support of multiple callbacks for same event in event management driver")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Link: https://lore.kernel.org/r/20240706065155.452764-1-cuigaosheng1@huawei.com
Signed-off-by: Michal Simek <michal.simek@amd.com>