If you connect a FX2LP device to any high speed host then FX2LP automatically swicthes to high speed mode. All the example projects that you are getting with the FX2LP DVK works in high speed. You can find the high speed USB descriptors in descr.a51 file (in each and every example project).
CY7C68013 by default comes up in High speed mode. If the host is a HS host, then FX2LP will be detected as a HS device. There is no need for any setting to be done for it to come up as HS device. Host and devcie negotiates via chirp sequence and if botha re HS capable comes up as a HS device.
But I have faced a problem. In the case of bulk loop example, after loading the iic file, when I open cyconsole I see that the maximum packet size for endpoints is set to 64. In dscr51.asm file, in full speed dscr table, maximum packet size for full speed is 64 and for high speed is 1024. Doesn't it mean the device is running in full speed mode?
Try using a different port and check if the same behaviour is repeating.