drm/amdgpu: fix division by zero with invalid uvd dimensions

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: fix division by zero with invalid uvd dimensions When width or height is less than 16, width_in_mb or height_in_mb becomes 0, leading to fs_in_mb being 0. This causes a division by zero when calculating num_dpb_buffer in H264 and H264 Perf decode paths. Add validation to reject frames with width < 16 or height < 16 before performing any calculations that depend on these values. V2: Format change - move up all vaiable definitions. V3: Use warn_once to avoid spam. (cherry picked from commit 3e41d26c70b0a459d041cc19482a226c4b7423cb)