gfxstream: don't forward declare ProcessResources

This avoids compilation errors when codegen'ing at build
time.

Reviewed-by: Aaron Ruby <aruby@blackberry.com>
Acked-by: Yonggang Luo <luoyonggang@gmail.com>
Acked-by: Adam Jackson <ajax@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/27246>

src/gfxstream/codegen/scripts/cereal/decoder.py

@@ -28,7 +28,6 @@ decoder_decl_preamble = """
 
 namespace gfxstream {
 class IOStream;
-class ProcessResources;
 }  // namespace gfxstream
 
 namespace gfxstream {

src/gfxstream/codegen/scripts/cerealgenerator.py

@@ -486,6 +486,7 @@ using DlSymFunc = void* (void*, const char*);
 
         decoderHeaderIncludes = f"""
 #include "VkDecoderContext.h"
+#include "host/ProcessResources.h"
 
 #include <memory>