codeowners: add entry for arm64 board mimx93_evk
Add myself to be owner for board mimx93_evk_a55.
/boards/arm64/mimx8mm_evk/ @MrVan @JiafeiPan
/boards/arm64/mimx8mp_evk/ @MrVan @JiafeiPan
/boards/arm64/mimx8mn_evk/ @JiafeiPan
+/boards/arm64/mimx93_evk/ @JiafeiPan
/boards/arm64/nxp_ls1046ardb/ @JiafeiPan
/boards/arm64/xenvm/ @lorc @firscity
/boards/arm64/fvp_baser_aemv8r/ @povergoing
