[host1x] FreeBSD: Fix random crashes due to CUDA/VAAPI check sideeffects (#64)

FreeBSD doesn't support NVDEC, CUDA, and partially supports VAAPI (mostly for firefox).
Implementing VAAPI for other use cases would be a little bit complicated so, I chose to switch it off for FreeBSD.
This PR ensures that FFmpeg will always default to software decoding on FreeBSD, but should remain the same functionalities for other OS's.
The results are slight CPU increases while decoding in software mode, but still neglectable and they don't really harm performance.

Co-authored-by: MaranBr <maranbr@eden-emu.dev>
Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/64
Co-authored-by: SDK-Chan <sdkchan@eden-emu.dev>
Co-committed-by: SDK-Chan <sdkchan@eden-emu.dev>

src/video_core/host1x/ffmpeg/ffmpeg.cpp

@@ -26,13 +26,14 @@ namespace {
 constexpr AVPixelFormat PreferredGpuFormat = AV_PIX_FMT_NV12;
 constexpr AVPixelFormat PreferredCpuFormat = AV_PIX_FMT_YUV420P;
 constexpr std::array PreferredGpuDecoders = {
-    AV_HWDEVICE_TYPE_CUDA,
 #ifdef _WIN32
+    AV_HWDEVICE_TYPE_CUDA,
     AV_HWDEVICE_TYPE_D3D11VA,
     AV_HWDEVICE_TYPE_DXVA2,
+#elif defined(__FreeBSD__)
+    AV_HWDEVICE_TYPE_VDPAU,
 #elif defined(__unix__)
     AV_HWDEVICE_TYPE_VAAPI,
-    AV_HWDEVICE_TYPE_VDPAU,
 #endif
     AV_HWDEVICE_TYPE_VULKAN,
 };