[otbn,dv] Fix regex for parsing loop warps
[otbn,dv] Fix regex for parsing loop warps

The plus should be inside the capture groups (but it still works for
single digit numbers, which is why I didn't realise the bug at
first!).

Signed-off-by: Rupert Swarbrick <290093e2ad2515ed2f14d749293c8cf8e02ca274@lowrisc.org>

lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan