This patch adds mapping for secure FLASH0 for qemu/virt and
qemu/qemu_sbsa platforms. This change is targeted for sbsa but since both
platforms share common code, changes in common defines was necessary.

For qemu_sbsa, this patch adds necessary mapping in order to boot without
semi-hosting from secure FLASH0. EFI need to stay in FLASH1 (share it with
variables) since it need to "run in place" in non secure domain. Changes
for this are under RFC at edk2-platforms mailing list:
https://patches.linaro.org/patch/171327/
(edk2-platforms/Platform/Qemu/SbsaQemu/SbsaQemu.dsc).

In docs qemu/virt is described as using semi-hosting, therefore this change
should be orthogonal to existing assumptions while giving possibility to
store both bl1 and fip in FLASH0 at some point (additional changes required
for that).

Signed-off-by: Radoslaw Biernacki <radoslaw.biernacki@linaro.org>
Change-Id: I782bc3637c91c01eaee680b3c5c408e24b4b6e28