hwmon: (w83773g) Select REGMAP_I2C to fix build error

Select REGMAP_I2C to avoid below build error:
ERROR: "__devm_regmap_init_i2c" [drivers/hwmon/w83773g.ko] undefined!

Fixes: ee249f27 ("hwmon: Add W83773G driver")
Cc: stable@vger.kernel.org
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>