ipmi:si: Move SI type information into an info structure

Andy reported:

Debian clang version 19.1.7 is not happy when compiled with
`make W=1` (note, CONFIG_WERROR=y is the default):

ipmi_si_platform.c:268:15: error: cast to smaller integer type 'enum si_type' from 'const void *' [-Werror,-Wvoid-pointer-to-enum-cast]
  268 |         io.si_type      = (enum si_type)device_get_match_data(&pdev->dev);

The IPMI SI type is an enum that was cast into a pointer that was
then cast into an enum again.  That's not the greatest style, so
instead create an info structure to hold the data and use that.

Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Closes: https://lore.kernel.org/lkml/20250415085156.446430-1-andriy.shevchenko@linux.intel.com/


Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Corey Minyard <corey@minyard.net>