drm/amdgpu: add upper bound check on user inputs in signal ioctl

In the Linux kernel, the following vulnerability has been resolved:

drm/amdgpu: add upper bound check on user inputs in signal ioctl

Huge input values in amdgpu_userq_signal_ioctl can lead to a OOM and

could be exploited.

So check these input value against AMDGPU_USERQ_MAX_HANDLES

which is big enough value for genuine use cases and could

potentially avoid OOM.

(cherry picked from commit be267e15f99bc97cbe202cd556717797cdcf79a5)