regmap: fix kcalloc() arguments order

When compiling with gcc version 14.0.0 20231220 (experimental)
and W=1, I've noticed a bunch of four similar warnings like:

drivers/base/regmap/regmap-ram.c: In function '__regmap_init_ram':
drivers/base/regmap/regmap-ram.c:68:37: warning: 'kcalloc' sizes specified with
'sizeof' in the earlier argument and not in the later argument [-Wcalloc-transposed-args]
68 | data->read = kcalloc(sizeof(bool), config->max_register + 1,
| ^~~~

Since 'n' and 'size' arguments of 'kcalloc()' are multiplied to
calculate the final size, their actual order doesn't affect the
result and so this is not a bug. But it's still worth to fix it.

Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Link: https://msgid.link/r/20231220175829.533700-1-dmantipov@yandex.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Add RAM backed register map

Add a register map that is a simple array of memory, for use in
KUnit testing of the framework. This is not exposed in regmap.h
since I can't think of a non-test use case, it is purely for use
internally. To facilitate testing we track if registers have been
read or written to.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230324-regmap-kunit-v2-1-b208801dc2c8@kernel.org