mfd: lpc_ich: Mark *_gpio_offsets data with const

There is no reason why the GPIO resource offsets should not be const.
Mark them accordingly and update a qualifier in struct lpc_ich_gpio_info
definition.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20231024160650.3898959-1-andriy.shevchenko@linux.intel.com


Signed-off-by: Lee Jones <lee@kernel.org>