OvmfPkg/MemEncryptSevLib: Address range encryption state interface
    
    BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3108
    
    Update the MemEncryptSevLib library to include an interface that can
    report the encryption state on a range of memory. The values will
    represent the range as being unencrypted, encrypted, a mix of unencrypted
    and encrypted, and error (e.g. ranges that aren't mapped).
    
    Cc: Jordan Justen <jordan.l.justen@intel.com>
    Cc: Laszlo Ersek <lersek@redhat.com>
    Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
    Cc: Brijesh Singh <brijesh.singh@amd.com>
    Acked-by: Laszlo Ersek <lersek@redhat.com>
    Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
    Message-Id: <0d98f4d42a2b67310c29bac7bcdcf1eda6835847.1610045305.git.thomas.lendacky@amd.com>