Blackfin: unify default I2C settings for ADI boards

include/configs/bf518f-ezbrd.h

include/configs/bf526-ezbrd.h

include/configs/bf527-ezkit.h

include/configs/bf533-ezkit.h

include/configs/bf533-stamp.h

include/configs/bf537-pnav.h

include/configs/bf537-stamp.h

include/configs/bf538f-ezkit.h

include/configs/bf548-ezkit.h

include/configs/bf561-ezkit.h

include/configs/bfin_adi_common.h

include/configs/cm-bf527.h

include/configs/cm-bf537e.h

include/configs/cm-bf537u.h

include/configs/cm-bf548.h

include/configs/ibf-dsp561.h

include/configs/tcm-bf518.h

include/configs/tcm-bf537.h