regmap: kunit: Use array_size() and sizeof(*ptr) consistently

regmap: kunit: Use array_size() and sizeof(*ptr) consistently

Some of the allocations use explit sizeof(type) instead of sizeof(*ptr),
which is fragile. In particular, stress_insert() allocates double
of memory without obvious need for a test. Convert all allocations
to use array_size() and sizeof(*ptr) to eliminate similar mistakes
or wrong memory sizes.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240606202102.3108729-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>