fix: restore buffer clearing in DMAClear function

src/video_core/buffer_cache/buffer_cache.h

@@ -265,7 +265,7 @@ bool BufferCache<P>::DMAClear(GPUVAddr dst_address, u64 amount, u32 value) {
     const BufferId buffer = FindBuffer(*cpu_dst_address, static_cast<u32>(size));
     Buffer& dest_buffer = slot_buffers[buffer];
     const u32 offset = dest_buffer.Offset(*cpu_dst_address);
-    // runtime.ClearBuffer(dest_buffer, offset, size, value);
+    runtime.ClearBuffer(dest_buffer, offset, size, value);
     dest_buffer.MarkUsage(offset, size);
     return true;
 }