x86/cpuid: Handle leaves 0x80000005-7 in guest_cpuid()

x86/cpuid: Handle leaves 0x80000005-7 in guest_cpuid()

Leaf 0x80000005 contains L1 cache/TLB information, 0x80000006 L2 & L3
cache/TLB information, and 0x80000007 Power management information.

Intel reserves all of this information other than the L2 cache information,
and the ITSC bit from the power management leaf.

AMD passes all of the cache/TLB information through to the guest, while most
of of the power management information is explicitly clobbered by the
toolstack.

0x80000007 edx (containing ITSC) is covered by the featureset logic.

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