regmap: Print error messages for ranges where the window and range overlap

We support accessed to paged register ranges, we describe these by having
the regmap assign a range of virtual register numbers to the underlying
registers and specify the window in the physical register map through which
they can be accessed, along with the register used to move the window.
Things get very confused if the window and virtual range overlap since it
is unclear how to access registers in the window, do we need to page to
them or not?

Unfortunately the code neither detects cases where the range and window
overlap nor blows up obviously when encountering them so we've got quite a
few broken drivers. Try to prevent any more creeping in by logging errors
if we see such regmaps.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Mark Brown <broonie@kernel.org>