Serial number regex not allowing non-hex characters

[mvolstad]

The USB serial number search limits the range to 0-9 and A-F.
Atmel EDBG device serial numbers contains the preample ATML. This is excluded from the search and therefore the COM-port detection does not work.

Proposal for fix in:
https://github.com/mvolstad/mbed-ls/tree/serialnumber_regex_fix

[ciarmcom]

ARM Internal Ref: IOTSYST-775

[PrzemekWirkus]

Actually it is not USB serial number but we are searching for target id of mbed-enabled device. Which is a ASCII hex string. The problem with board you have might be with the way we parse whole USB ID. I need to deeper into that.