Fix Clang-cl warning

[vukihub]

Describe
It is not a real bug, it is a warning to pay attention and fix.
The warning appears when compile with clang-cl compiler under Windows:

framework\aregextend/service/NESystemService.hpp(193,14): warning : enumeration value 'CMD_Custom' not explicitly handled in switch [-Wswitch-enum] [D:\a\areg-sdk\areg-sdk\product\cache\llvm-clang-cl\aregextend.vcxproj]

To Reproduce
Compile sources using CMake and clang-cl compiler.

Expected behavior
There should be no warning. Otherwise, suppress the warning.

Desktop or embedded (please complete the following information):

• OS: Windows
• Compiler: clang-cl
• AREG SDK version: latest in master