Davinci I2C initialization infrastructure; will be used by EVM init.

[ dbrownell@users.sourceforge.net: pass platform data into init code ]
Signed-off-by: NKomal Shah <komal_shah802003@yahoo.com>
Signed-off-by: NKevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>