KVM: SVM: Decrypt SEV VMSA in dump_vmcb() if debugging is enabled

KVM: SVM: Decrypt SEV VMSA in dump_vmcb() if debugging is enabled

An SEV-ES/SEV-SNP VM save area (VMSA) can be decrypted if the guest
policy allows debugging. Update the dump_vmcb() routine to output
some of the SEV VMSA contents if possible. This can be useful for
debug purposes.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Kim Phillips <kim.phillips@amd.com>
Link: https://lore.kernel.org/r/ea3b852c295b6f4b200925ed6b6e2c90d9475e71.1742477213.git.thomas.lendacky@amd.com
Signed-off-by: Sean Christopherson <seanjc@google.com>