Documentation: KVM: Synchronize x86 VM types

Documentation: KVM: Synchronize x86 VM types

KVM has reflected KVM_X86_SNP_VM to userspace since 1dfe571c12cf
("KVM: SEV: Add initial SEV-SNP support"), and KVM_X86_TDX_VM since
161d34609f9b ("KVM: TDX: Make TDX VM type supported"). Update the
documentation to reflect this fact.

Fixes: 1dfe571c12cf ("KVM: SEV: Add initial SEV-SNP support")
Fixes: 161d34609f9b ("KVM: TDX: Make TDX VM type supported")
Signed-off-by: Carlos López <clopez@suse.de>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Link: https://patch.msgid.link/20260603114504.814647-2-clopez@suse.de
[sean: use one tab instead of two]
Signed-off-by: Sean Christopherson <seanjc@google.com>