liboffloadmic plugin: Address -Wnarrowing diagnostics

liboffloadmic plugin: Address -Wnarrowing diagnostics

    libtool: compile:  [...]/build-gcc/./gcc/xg++ [...] -c [...]/source-gcc/liboffloadmic/plugin/libgomp-plugin-intelmic.cpp [...]
    In file included from [...]/source-gcc/liboffloadmic/plugin/libgomp-plugin-intelmic.cpp:40:0:
    [...]/install/offload-x86_64-intelmicemul-linux-gnu/lib/gcc/x86_64-intelmicemul-linux-gnu/6.0.0/include/main_target_image.h:8628:1: error: narrowing conversion of '192' from 'int' to 'char' inside { } [-Wnarrowing]
     };
     ^
    [...]/install/offload-x86_64-intelmicemul-linux-gnu/lib/gcc/x86_64-intelmicemul-linux-gnu/6.0.0/include/main_target_image.h:8628:1: error: narrowing conversion of '192' from 'int' to 'char' inside { } [-Wnarrowing]
    [...]/install/offload-x86_64-intelmicemul-linux-gnu/lib/gcc/x86_64-intelmicemul-linux-gnu/6.0.0/include/main_target_image.h:8628:1: error: narrowing conversion of '164' from 'int' to 'char' inside { } [-Wnarrowing]
    [many more]

	liboffloadmic/
	* plugin/Makefile.am (main_target_image.h): Change type of data
	member in struct MainTargetImage to uint8_t.
	* plugin/Makefile.in: Regenerate.

From-SVN: r225562