x86/cpufeatures: use cpu_data in init_scattered_cpuid_flags()

x86/cpufeatures: use cpu_data in init_scattered_cpuid_flags()

Post SMP init, cpu_data() contains the current cpuinfo state with
the boot_cpu_data potentially going stale.

Switch all boot_cpu_data references to cpu_data() in
init_scattered_cpuid_flags().

Orabug: 27878230

Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: John Haxby <john.haxby@oracle.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
(cherry-picked from commit 6258d6d6ce2b9cf41830e8616ffc7841b3fddca9)

Conflict:
  arch/x86/kernel/cpu/common.c

[Backport: Modify init_scattered_cpuid_flags() instead of
 init_speculation_control().]

Signed-off-by: Brian Maly <brian.maly@oracle.com>