ARM64: dts: meson-gx: fix ATF reserved memory region

ARM64: dts: meson-gx: fix ATF reserved memory region

BugLink: http://bugs.launchpad.net/bugs/1807469
commit 48e21ded0432ee1e2359d4143d7a6925cefee1b5 upstream.

Vendor firmware/uboot has different reserved regions depending on
firmware version, but current codebase reserves the same regions on
GXL and GXBB, so move the additional reserved memory region to common
.dtsi.

Found when putting a recent vendor u-boot on meson-gxbb-p200.

Suggested-by: Neil Armstrong <narmstrong@baylibre.com>
Cc: stable@vger.kernel.org
Signed-off-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>