MAINTAINERS: Update MAINTAINERS file for wasm-related files

Signed-off-by: Kohei Tokunaga <[email protected]>

Author: ktock

MAINTAINERS

@@ -3903,6 +3903,15 @@ F: tcg/tci/
 F: tcg/tci.c
 F: disas/tci.c
 
+WebAssembly TCG target
+M: Kohei Tokunaga <[email protected]>
+S: Maintained
+F: configs/meson/emscripten.txt
+F: tests/docker/dockerfiles/emsdk-wasm32-cross.docker
+F: util/coroutine-wasm.c
+F: os-wasm.c
+F: include/system/os-wasm.h
+
 Block drivers
 -------------
 VMDK