patch 9.1.0972: filetype: TI linker map files are not recognized

Problem:  filetype: TI linker map files are not recognized
Solution: detect TI linker map files as lnkmap filetype
          (Wu, Zhenyu)

References:
https://downloads.ti.com/docs/esd/SPRUI03A/Content/SPRUI03A_HTML/linker_description.html

closes: #16324

Signed-off-by: Wu, Zhenyu <wuzhenyu@ustc.edu>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/ftplugin/lnkmap.vim b/runtime/ftplugin/lnkmap.vim
new file mode 100644
index 0000000..46fb070
--- /dev/null
+++ b/runtime/ftplugin/lnkmap.vim
@@ -0,0 +1,16 @@
+" Vim filetype plugin file
+" Language:	TI Linker map
+" Document:	https://downloads.ti.com/docs/esd/SPRUI03A/Content/SPRUI03A_HTML/linker_description.html
+" Maintainer:	Wu, Zhenyu <wuzhenyu@ustc.edu>
+" Last Change:	2024 Dec 25
+
+if exists("b:did_ftplugin")
+  finish
+endif
+
+" Don't load another plugin for this buffer
+let b:did_ftplugin = 1
+
+let b:undo_ftplugin = "setl iskeyword<"
+
+setl iskeyword+=.