Support a FatFS in a serail flashmemory after checking microSD.
Support a multi partition feature.
Make sure a SPI_FLASH_ONLY feature.
Change parameters of ftpd_init function.
Change ftp.control&data to CTRL_SOCK&DATA_SOCK.
Fix a confliction of memory temporarily.
Merge branch 'WIZ550web_ftpserver' into WIZ550web_dev