mfd: da9062: Support SMBus and I2C mode

Enable the I2C bus mode if I2C_FUNC_I2C is set. Based on da6093 commit:
"586478bf mfd: da9063: Support SMBus and I2C mode"

Signed-off-by: Andrej Picej <andrej.picej@norik.com>
Reviewed-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20211124065119.2514872-1-andrej.picej@norik.com