ArmVirtPkg: handle NETWORK_TLS_ENABLE in ArmVirtQemu*

ArmVirtPkg: handle NETWORK_TLS_ENABLE in ArmVirtQemu*

Port the [LibraryClasses], [PcdsFixedAtBuild] and [Components] settings
that are related to NETWORK_TLS_ENABLE from OvmfPkg to ArmVirtPkg.
ArmVirtXen is not modified because it doesn't include the edk2 network
stack.

(This change is now simpler than it would have been when TianoCore#1009
was originally filed, due to ArmVirtPkg consuming the NetworkPkg include
fragments meanwhile, from TianoCore#1293 / commit 157a3b1aa50f.)

The usage hints from "OvmfPkg/README", section "HTTPS Boot", apply.

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Gary Lin <glin@suse.com>
Cc: Guillaume GARDET <guillaume.gardet@arm.com>
Cc: Julien Grall <julien.grall@arm.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1009
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Guillaume Gardet <guillaume.gardet@arm.com>
Reviewed-by: Philippe Mathieu-Daude <philmd@redhat.com>
Tested-by: Gary Lin <glin@suse.com>