i2c: sh_mobile: drop 'data' argument from i2c_op function

It is clear that we always send the address in TX_FIRST and data in TX.
No need to pass it from the caller.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>