sunos: fix uv_cpu_info() on x86_64
sunos: fix uv_cpu_info() on x86_64

kstat_data_lookup("clock_Mhz") returns a KSTAT_DATA_INT32 on i386 but a
KSTAT_DATA_INT64 on x86_64.

urbit/archaeology2,urbit/archaeology2,unknownbrackets/maxcso,urbit/archaeology2,urbit/archaeology2,unknownbrackets/maxcso,urbit/archaeology2,unknownbrackets/maxcso,urbit/archaeology2,urbit/archaeology2,unknownbrackets/maxcso,urbit/archaeology2,unknownbrackets/maxcso,urbit/archaeology2,unknownbrackets/maxcso,unknownbrackets/maxcso