x86/msr: Use the architectural layout for MSR_{MISC_ENABLES,PLATFORM_INFO}

x86/msr: Use the architectural layout for MSR_{MISC_ENABLES,PLATFORM_INFO}

This simplifies future interactions with the toolstack, by removing the need
for per-MSR custom accessors when shuffling data in/out of a policy.

Use a 32bit raw backing integer (for simplicity), and use a bitfield to move
the cpuid_faulting field to its appropriate position.

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