x86/mm: Fix spacing within memory encryption features message

The spacing is off in the memory encryption features message on AMD
platforms that support memory encryption, e.g.:

  "Memory Encryption Features active:AMD  SEV SEV-ES"

There is no space before "AMD" and two spaces after it. Fix this so that
the message is spaced properly:

  "Memory Encryption Features active: AMD SEV SEV-ES"

Fixes: 968b4931 ("x86/mm: Make DMA memory shared for TD guest")
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Link: https://lkml.kernel.org/r/02401f3024b18e90bc2508147e22e729436cb6d9.1650298573.git.thomas.lendacky@amd.com