x86/tsx: Cope with TSX deprecation on SKL/KBL/CFL/WHL

x86/tsx: Cope with TSX deprecation on SKL/KBL/CFL/WHL

The June 2021 microcode is formally de-featuring TSX on the older Skylake
client CPUs.  The workaround from the March 2019 microcode is being dropped,
and replaced with additions to MSR_TSX_FORCE_ABORT to hide the HLE/RTM CPUID
bits.

With this microcode in place, TSX is disabled by default on these CPUs.
Backwards compatibility is provided in the same way as for TAA - RTM force
aborts, rather than suffering #UD, and the CPUID bits can be hidden to recover
performance.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>