regulator: max14577-regulator: Demote kerneldoc header to standard comment

Nothing about this comment identifies it as a kerneldoc header.
It's missing all of it's function argument descriptions and the
correct function header.

Fixes the following W=1 warning(s):

 drivers/regulator/max14577-regulator.c:166: warning: Function parameter or member 'max14577' not described in 'max14577_get_regma
 drivers/regulator/max14577-regulator.c:166: warning: Function parameter or member 'reg_id' not described in 'max14577_get_regmap'

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20200625163614.4001403-11-lee.jones@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>