Hyundai CAN FD: use less of the part number for fuzzy FP

[sshane]

We're getting PRs like #29962 and #29988 (ignore new part date) where the part number's suffix increments indicating some sort of part revision, but the major first two characters remain the same. Explore reducing the part number for fingerprinting to just the first characters. It still catches the Tucson with the different tuning, as well as #29949 which we don't want to merge for the same reason.

Similar to #29572

[sshane]

#30020 would also fingerprint with this.

[sshane]

Something like this: 47207e2

[sshane]

Though we do have to be careful. Here's an example of the same first two characters in the part number for a new 2024 Elantra fwdRadar, however they switched from having it send SCC to just being a radar. The only thing that would prevent it from matching with this is the date code in the camera (which also has the same first two characters). #30219

• Consider SCC/RDR or decide this is safe with plaintext date code

dongle: 784a39c0a9dd3493

# 2021
b'\xf1\x00CN7_ SCC FNCUP      1.00 1.01 99110-AA000         ',
# 2024
b'\xf1\x00CN7_ RDR -----      1.00 1.01 99110-AA500         ',

[gregjhogan]

Fuzzy fingerprinting on things we understand (platform codes, dates, software version numbers) seems fairly safe. I am not sure how we make any safe assumptions about the future if extend to components we don't understand what the values represent.

[sshane]

We don't understand the part numbers enough yet for this. Can revisit in the future