patch 9.1.0873: filetype: Vivado files are not recognized

Problem:  filetype: Vivado files are not recognized
Solution: detect '*.mss' files as 'mss' filetype
          (Wu, Zhenyu)

references:
https://docs.amd.com/r/2020.2-English/ug1400-vitis-embedded/Microprocessor-Software-Specification-MSS

closes: #15907

Signed-off-by: Wu, Zhenyu <wuzhenyu@ustc.edu>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/ftplugin/mss.vim b/runtime/ftplugin/mss.vim
new file mode 100644
index 0000000..de2f879
--- /dev/null
+++ b/runtime/ftplugin/mss.vim
@@ -0,0 +1,16 @@
+" Vim filetype plugin file
+" Language:	Vivado mss file
+" Last Change:	2024 Oct 22
+" Document:	https://docs.amd.com/r/2020.2-English/ug1400-vitis-embedded/Microprocessor-Software-Specification-MSS
+" Maintainer:	Wu, Zhenyu <wuzhenyu@ustc.edu>
+
+if exists("b:did_ftplugin")
+  finish
+endif
+let b:did_ftplugin = 1
+
+setlocal comments=b:#,fb:-
+setlocal commentstring=#\ %s
+
+let b:match_words = '\<BEGIN\>:\<END\>'
+let b:undo_ftplugin = "setl com< cms< | unlet b:match_words"