Exempt from strict warnings for struct packing and add MCU options

src/class/cdc/cdc.h

@@ -50,6 +50,10 @@
  extern "C" {
 #endif
 
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wpacked"
+#pragma GCC diagnostic ignored "-Wattributes"
+
 /** \defgroup ClassDriver_CDC_Common Common Definitions
  *  @{ */
 
@@ -401,6 +405,8 @@ typedef struct ATTR_PACKED
 
 TU_VERIFY_STATIC(sizeof(cdc_line_control_state_t) == 2, "size is not correct");
 
+#pragma GCC diagnostic pop
+
 /** @} */
 
 #ifdef __cplusplus