set the default target and board to sam and adk2
set the default target and board to sam and adk2

Change-Id: I531d14a45a838eaf2ac8fc95c8087e9ad4397348

xin3liang/platform_external_arduino-ide,xin3liang/platform_external_arduino-ide,xin3liang/platform_external_arduino-ide,xin3liang/platform_external_arduino-ide,xin3liang/platform_external_arduino-ide,xin3liang/platform_external_arduino-ide,xin3liang/platform_external_arduino-ide