x86: Perform late TSC calibration before LAPIC timer calibration

This ensures that LAPIC calibration is done using the correct tsc_freq
value, i.e., the one associated with the TSC timecounter. It does mean
though that TSC calibration cannot use sbinuptime() to read the
reference timecounter, as timehands are not yet set up.

Reviewed by: kib, jhb
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D33209