edgeport-ti: use request_firmware()

Firmware blob looks like this...
        uint8_t  MajorVersion
        uint8_t  MinorVersion
        __le16   BuildNumber
        uint8_t  data[]

Signed-off-by: Jaswinder Singh <jaswinder@infradead.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>