CC_ATTR_HOST_MEM_ENCRYPT is used to relay that memory encryption has been
activated by the kernel.

As it's technically possible to enable both SME and TSME at the same time,
detect this scenario and notify the user that enabling TSME and SME at the
same time is unnecessary.
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>