hyperv: Wait 5 seconds for hyperv result, instead of 500ms
This addresses various devices (network, stoarge) attach failure.
Reported by: Hongxiong Xian <v-hoxian microsoft com>
Tested by: Hongxiong Xian <v-hoxian microsoft com>
MFC after: 1 week
Sponsored by: Microsoft OSTC
Differential Revision: https://reviews.freebsd.org/D5435