Add entry in the MAINTAINERS file for the Nitro Enclaves files such as
the documentation, the header files, the driver itself and the user
space sample.

Changelog

v9 -> v10

* Update commit message to include the changelog before the SoB tag(s).

v8 -> v9

* Update the location of the documentation, as it has been moved to the
  "virt" directory.

v7 -> v8

* No changes.

v6 -> v7

* No changes.

v5 -> v6

* No changes.

v4 -> v5

* No changes.

v3 -> v4

* No changes.

v2 -> v3

* Update file entries to be in alphabetical order.

v1 -> v2

* No changes.
Reviewed-by: Alexander Graf <graf@amazon.com>
Signed-off-by: Andra Paraschiv <andraprs@amazon.com>
Link: https://lore.kernel.org/r/20200921121732.44291-19-andraprs@amazon.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>