[POWERPC] fsl_soc: fix uninitialized i2c_board_info structure

i2c_board_info used semi-initialized, causing garbage in the
info->flags, and that, in turn, causes various symptoms of i2c
malfunctioning, like PEC mismatches.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>