AP_BoardConfig → AP_Common Relation

File in libraries/AP_BoardConfig	Includes file in libraries/AP_Common
AP_BoardConfig.cpp	AP_Common.h
AP_BoardConfig.h	AP_Common.h
AP_BoardConfig_CAN.cpp	AP_Common.h
AP_BoardConfig_CAN.h	AP_Common.h
canbus.cpp	AP_Common.h
canbus_driver.cpp	AP_Common.h
px4_drivers.cpp	missing / fcntl.h