i2c: constify platform_device_id

The platform_device_id is not modified by these drivers and core uses it
as const.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

diff --cc drivers/i2c/busses/i2c-imx.c
Simple merge

diff --cc drivers/i2c/busses/i2c-mxs.c
Simple merge

diff --cc drivers/i2c/busses/i2c-rcar.c
Simple merge

diff --cc drivers/i2c/busses/i2c-s3c2410.c
Simple merge