crc32: Buffer up log output to avoid prefix-chunking, fix `func`

Detailed description

This is a fix to one of my edited/contributed features regarding compare-sections via qCRC.
There are three existing problems, which are not critical to upstream BMD here.
This PR updates crc32 dispatch code to deal with them.

Because of #1713 and requirements to support Windows and MacOS (cross-platform portable software), the __func__ portion of log became identical as collateral damage. This change restores the behaviour intended in #1708, so that we can tell apart speed reports from BMF+ENABLE_DEBUG and BMDA.
On out-of-tree platforms like Farpatch which use BMD as a git submodule directly, custom logger implementations format every DEBUG_INFO() call etc. by prepending loglevel and timestamp, so the 2-3 piece logmessage gets broken and mixed. This change buffers the optional output pieces into a zeroed stack buffer via snprintf() to avoid that.
Xtensa Farpatch crashes on every divide-by-zero, which can happen here when <1 milliseconds are reported elapsed by corresponding platform timing code. BMF on Cortex-M3 does not trap integer divide-by-zero into UsageFault, so it was never affected. BMDA usually gets more than 1ms due to USB FS delays and all the layer overheads. This change skips the speed report by checking for both length and time to be big enough.

[x] I've read the Code of Conduct
[x] I've read the guidelines for contributing to this repository
[x] It builds for hardware native (see Building the firmware)
[x] It builds as BMDA (see Building the BMDA)
[x] I've tested it to the best of my ability
[x] My commit messages provide a useful short description of what the commits do

Fixes some issues in Farpatch.