fast-get: limit scope

fast-get is only needed when DRAM is used, i.e. when
CONFIG_COLD_STORE_EXECUTE_DRAM is selectef. It's also unneeded in
modules when CONFIG_LLEXT_TYPE_ELF_SHAREDLIB is used, i.e. in gcc
builds, because also in those builds no .cold and .coldrodata
sections are created.

Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>

Author: lyakh

Kconfig.sof

@@ -39,6 +39,7 @@ config COLD_STORE_EXECUTE_DEBUG
 
 config FAST_GET
 	bool "Enable simple refcounting DRAM data copier"
+	depends on COLD_STORE_EXECUTE_DRAM
 	help
 	  Enable simple refcounting DRAM data copier for copying processing
 	  module data from DRAM to SRAM when the data is needed and freeing

src/include/sof/lib/fast-get.h

@@ -12,7 +12,17 @@
 
 struct k_heap;
 
+#if (CONFIG_COLD_STORE_EXECUTE_DRAM &&					\
+	(CONFIG_LLEXT_TYPE_ELF_RELOCATABLE || !defined(LL_EXTENSION_BUILD))) || \
+	!CONFIG_SOF_FULL_ZEPHYR_APPLICATION
 const void *fast_get(struct k_heap *heap, const void * const dram_ptr, size_t size);
 void fast_put(struct k_heap *heap, const void *sram_ptr);
+#else
+static inline const void *fast_get(struct k_heap *heap, const void * const dram_ptr, size_t size)
+{
+	return dram_ptr;
+}
+static inline void fast_put(struct k_heap *heap, const void *sram_ptr) {}
+#endif
 
 #endif /* __SOF_LIB_FAST_GET_H__ */