tests/sys/kern/crc32: Check for SSE4.2 before using it

This avoids a SIGILL when running these tests on QEMU (which
defaults to a basic amd64 CPU without SSE4.2).

This commit also tests the table-based implementations in addition to
testing the hw-accelerated crc32 versions.

Reviewed By: cem, kib, markj
Differential Revision: https://reviews.freebsd.org/D28395