i2c: Add i2c_get_match_data()

Add i2c_get_match_data() to get match data for I2C, ACPI and
DT-based matching, so that we can optimize the driver code.

Suggested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
[wsa: simplified var initialization]
Signed-off-by: Wolfram Sang <wsa@kernel.org>