bootloader: Implement TSC calibration via hypervisor CPUID leaf.

While debugging some problems on the HaikuPorts build VMs, mmlr
noticed their clocks had an alarming amount of drift. This prompted
an investigation into TSC calibration mechanisms, and the discovery
that there is a VM-specific one which we did not implement.

This mechanism is more accurate than counting cycles on VMs where
cycles can be "stolen" (the probable cause of the aforementioned
clock drift.)

Tested in VMware (works out of the box) and on QEMU/KVM
(may need TSC frequency specified or a host with invariant TSC.)

Change-Id: I4ccfdb2e4e2621404ec9026e7106c02bf96faf18
Reviewed-on: https://review.haiku-os.org/c/haiku/+/7063
Reviewed-by: waddlesplash <waddlesplash@gmail.com>

boot/efi/x86: implement timer initialization

Change-Id: Ida16e63d2b8f87b90897892faf0e6db92b185d34
Reviewed-on: https://review.haiku-os.org/c/haiku/+/4851
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>

boot/efi: add stubs for x86

Change-Id: I8d3dfa7cc07679a8b024df24f7cddb3a5bcec02c
Reviewed-on: https://review.haiku-os.org/c/haiku/+/4747
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>
Reviewed-by: Jérôme Duval <jerome.duval@gmail.com>