Activate i2c2 bus in r8a7793/gose device tree.

Based on similar work for the r8a7791/koelsch by Wolfram Sang.
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>