app: aboot: replace strtok with strtok_r
app: aboot: replace strtok with strtok_r

strtok is banned replace it with strtok_r

CRs-Fixed: 1017009

Change-Id: I84551015bcb15eea3b63c8c7578c54c268d286d7

efidroid/lk,efidroid/lk,efidroid/lk,efidroid/lk,efidroid/lk