Add missing --preinclude and -input on assembly files

Except for IAR, it does not support the --preinclude option for assembly
files but all of the other exporters can. It was less code to remove it
in IAR than to explicitly add it in all of the other exporters.

Author: theotherjimmy

tools/export/exporters.py

@@ -62,6 +62,7 @@ def progen_flags(self):
             if self.config_header:
                 self._progen_flag_cache['c_flags'] += self.toolchain.get_config_option(self.config_header)
                 self._progen_flag_cache['cxx_flags'] += self.toolchain.get_config_option(self.config_header)
+                self._progen_flag_cache['asm_flags'] += self.toolchain.get_config_option(self.config_header)
         return self._progen_flag_cache
 
     def __scan_and_copy(self, src_path, trg_path):

tools/export/iar.py

@@ -76,6 +76,8 @@ def generate(self, progen_build=False):
         project_data['tool_specific']['iar'].setdefault("misc", {})
         project_data['tool_specific']['iar'].update(tool_specific['iar'])
         project_data['tool_specific']['iar']['misc'].update(self.progen_flags)
+        project_data['tool_specific']['iar']['misc']['asm_flags'].remove(
+            self.toolchain.get_config_option(self.config_header)[0])
         # VLA is enabled via template IccAllowVLA
         project_data['tool_specific']['iar']['misc']['c_flags'].remove("--vla")
         project_data['common']['build_dir'] = os.path.join(project_data['common']['build_dir'], 'iar_arm')