The bug is not in that commit, the Kconfig entry for this driver is
missing a 'select REGMAP_I2C'. I just tested it and then it builds
without any issues.
I can send a patch to fix that, but I would like to know what commit it
really fixes: the one that introduced the driver as it already used
regmap and did not include the required select? Or the one from this
report because it triggered, even though it is not the real source of
the issue?