x86/platform/uv: When searching for minimums, start at INT_MAX not 99999

Using a starting value of INT_MAX rather than 999999 or 99999 means
this algorithm won't fail should the numbers being compared ever
exceed this value.

Signed-off-by: Steve Wahl <steve.wahl@hpe.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/all/20230519190752.3297140-5-steve.wahl%40hpe.com