Update mpsse.i

[crossleyjo]

I found that calling the SetDirection function from python led to a TypeError due to the uint8_t parameter in the function declaration

int SetDirection(struct mpsse_context *mpsse, uint8_t direction);

Stack exchange said I could just include stdint.i in the mpsse.i file. I recompiled and confirmed that the error disappeared.

https://stackoverflow.com/questions/8897294/swig-python-c-how-to-use-type-int8-t