pinctrl: cy8c95x0: Avoid accessing reserved registers

The checks for vrtual registers in the cy8c95x0_readable_register()
and cy8c95x0_writeable_register() are not aligned and broken.

Fix that by explicitly avoiding reserved registers to be accessed.

Fixes: 71e4001a ("pinctrl: pinctrl-cy8c95x0: Fix regcache")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/20250203131506.3318201-3-andriy.shevchenko@linux.intel.com


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>