Memtest86+: Support faster reference clocks for UARTs

Most UARTs run from 1.8432 MHz, but this is not always true. The
lb_serial table will let us know.

Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Change-Id: I27bba158773a08cafe0daf5698b1bdefcd951c45
Reviewed-on: https://review.coreboot.org/c/memtest86plus/+/37060
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
1 file changed