nv2a: Const-ify some function parameters

hw/xbox/nv2a/pgraph/gl/shaders.c

@@ -184,7 +184,7 @@ static bool shader_module_cache_entry_compare(Lru *lru, LruNode *node,
 }
 
 static GLuint get_shader_module_for_key(PGRAPHGLState *r,
-                                        ShaderModuleCacheKey *key)
+                                        const ShaderModuleCacheKey *key)
 {
     uint64_t hash = fast_hash((void *)key, sizeof(ShaderModuleCacheKey));
     LruNode *node = lru_lookup(&r->shader_module_cache, hash, key);

hw/xbox/nv2a/pgraph/vk/shaders.c

@@ -416,7 +416,7 @@ static void shader_cache_finalize(PGRAPHState *pg)
 }
 
 static ShaderBinding *get_shader_binding_for_state(PGRAPHVkState *r,
-                                                   ShaderState *state)
+                                                   const ShaderState *state)
 {
     uint64_t hash = fast_hash((void *)state, sizeof(*state));
     LruNode *node = lru_lookup(&r->shader_cache, hash, state);