clk: twl: add clock driver for TWL6032

The TWL6032 has some clock outputs which are controlled like
fixed-voltage regulators, in some drivers for these chips
found in the wild, just the regulator api is abused for controlling
them, so simply use something similar to the regulator functions.
Due to a lack of hardware available for testing, leave out the
TWL6030-specific part of those functions.

Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
Link: https://lore.kernel.org/r/20230916100515.1650336-5-andreas@kemnade.info
Signed-off-by: Stephen Boyd <sboyd@kernel.org>