i2c: sh_mobile: use proper device for mapping DMA memory

It should be the DMA device, not the platform device.

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