Enhance the base/rom extension to generate the symbol file of the rom built.
The symbol file is placed in epoc32/rom/<baseport_name>, along with the rom log and final oby file.
T_SERIAL OK
T_SOUND OK except for FreeLogicalDevice bits
T_ATADRV OK
T_IDRV OK
T_PCCD1 Not yet implemented
T_PCCD2 Not yet implemented
T_PCCD3 Not yet implemented
T_POWR OK
T_HAL OK
T_INF OK
T_PTNOS Not yet implemented
T_RESET
T_PS OK
T_COLOUR OK
T_WWINS OK