Problem: filetype: TI assembly files are not recognized
Solution: inspect '*.sa' and assembly files and detect TI assembly
files, include filetype plugin and syntax script for TI
assembly files (Wu, Zhenyu)
closes: #15827
Signed-off-by: Wu, Zhenyu <wuzhenyu@ustc.edu>
Signed-off-by: Christian Brabandt <cb@256bit.org>
