mfd: intel_soc_pmic_bxtwc: Use temporary variable for struct device

Use a temporary variable for the struct device pointers to avoid
dereferencing. This makes code a bit neater.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20241016105201.757024-4-andriy.shevchenko@linux.intel.com


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