mfd: kempld: Remove custom DMI matching code

The ->init() open codes the functionality of DMI matching code.
Moreover, all DMI quirks are using the same callback and driver_data.
With this in mind, refactor the DMI matching code.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240423210706.3709568-1-andriy.shevchenko@linux.intel.comSigned-off-by: Lee Jones <lee@kernel.org>