STM32F4 add Export compile binary option

Author: rogerclarkmelbourne

STM32F4/platform.txt

@@ -96,6 +96,10 @@ recipe.size.pattern="{compiler.path}{compiler.size.cmd}" -A "{build.path}/{build
 recipe.size.regex=^(?:\.text|\.rodata|\.ARM.exidx)\s+([0-9]+).*
 recipe.size.regex.data=^(?:\.data|\.bss|\.noinit)\s+([0-9]+).*
 
+## Save Compiled Binary
+recipe.output.tmp_file={build.project_name}.bin
+recipe.output.save_file={build.project_name}.{build.variant}.bin
+
 # Uploader tools
 # -------------------