ipmi: Re-use existing macros for built-in properties

Replace home grown set_prop_entry() macro by generic
PROPERTY_ENTRY_INTEGER()-like ones.

Cc: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>