I actually just ran across this issue today at work. There is an error in the *.tlc file that generates the C code. Just as an FYI, I am trying to compile this for the F28377S Launchpad.
Here is the file that I had to change to get things working. Of course, some of the directory names might be different for you. C:\MATLAB\SupportPackages\R2016aPrerelease\toolbox\target\supportpackages\tic2000\tlc_c\ti_c28x_init_sci.tlc
Once in the file, I went down to line 165 (hopefully the same line in your file) and changed it to the following:
It had "TXFIFOXRESET" and after looking in TI's technical reference manual, it appears that is just a typo and the X should not be in the name... The technical reference manual is located here (I was looking on page 1929 or so):
I hope this fixes your issue. Not quite sure how to report this as a bug to Mathworks.