Ticket #5003: highlight Kconfig output files

* .config is already highlighted as Java properties => reuse it. It is not ideal, but better than nothing.
* Additionally hightlight:
  - .config.* - e.g. .config.old produced by Kconfig.
  - *defconfig - used in Linux kernel, Buildroot, Busybox, U-Boot, Zephyr.
* Kconfig.defconfig should still be treated as Kconfig definition file, not as its output.

Signed-off-by: Sergey Naumov <sknaumov@gmail.com>
Signed-off-by: Yury V. Zaytsev <yury@shurup.com>

Author: sknaumov

misc/syntax/Syntax.in

@@ -378,5 +378,8 @@ include tree-meta.syntax
 file (/Kconfig(\\.[A-z0-9-]\+)?|/Config\\.(in|src)(\\.[A-z0-9-]\+)?|.\*\\.kconf(ig)?)$ Kconfig
 include kconfig.syntax
 
+file ..\*(\\.config(\\.[A-z0-9-]\+)?|defconfig)$ Kconfig\soutput
+include properties.syntax
+
 file .\* unknown
 include unknown.syntax