Add KNN and Hell fire demos. Update nanosoc system

nanosoc_board/C_Cxx/CMakeLists.txt

nanosoc_board/C_Cxx/fast_knn_demo2/CMakeLists.txt

nanosoc_board/C_Cxx/fast_knn_demo2/fast_knn_demo2.cpp

nanosoc_board/C_Cxx/fast_knn_demo2/hardware_config.c

nanosoc_board/C_Cxx/srimanth_demo/CMakeLists.txt

nanosoc_board/C_Cxx/srimanth_demo/hardware_config.c

nanosoc_board/C_Cxx/srimanth_demo/srimanth_demo.cpp

.../C_Cxx/system/nanosoc_board_system/nanosoc_board_system.c

.../C_Cxx/system/nanosoc_board_system/nanosoc_board_system.h

..._board/C_Cxx/system/nanosoc_graphics/nanosoc_graphics.cpp

..._board/C_Cxx/system/nanosoc_graphics/nanosoc_graphics.hpp