x86/Intel: unlock CPUID earlier for the BSP

x86/Intel: unlock CPUID earlier for the BSP

Intel CPUs have a MSR bit to limit CPUID enumeration to leaf two. If
this bit is set by the BIOS then CPUID evaluation does not work when
data from any leaf greater than two is needed; early_cpu_init() in
particular wants to collect leaf 7 data.

Cure this by unlocking CPUID right before evaluating anything which
depends on the maximum CPUID leaf being greater than two.

Inspired by (and description cloned from) Linux commit 0c2f6d04619e
("x86/topology/intel: Unlock CPUID before evaluating anything").

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>