ARM64: dts: meson-gxl: Add alternate ARM Trusted Firmware reserved memory zone

ARM64: dts: meson-gxl: Add alternate ARM Trusted Firmware reserved memory zone

commit 4ee8e51b9edfe7845a094690a365c844e5a35b4b upstream.

This year, Amlogic updated the ARM Trusted Firmware reserved memory mapping
for Meson GXL SoCs and products sold since May 2017 uses this alternate
reserved memory mapping.
But products had been sold using the previous mapping.

This issue has been explained in [1] and a dynamic solution is yet to be
found to avoid loosing another 3Mbytes of reservable memory.

In the meantime, this patch adds this alternate memory zone only for
the GXL and GXM SoCs since GXBB based new products stopped earlier.

[1] http://lists.infradead.org/pipermail/linux-amlogic/2017-October/004860.html

Fixes: bba8e3f42736 ("ARM64: dts: meson-gx: Add firmware reserved memory zones")
Reported-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>