ARM: boot: dts: bcm2711: Fix HVS register range

While the HVS has the same context memory size in the BCM2711 than in
the previous SoCs, the range allocated to the registers doubled and it
now takes 16k + 16k, compared to 8k + 16k before.

The KMS driver will use the whole context RAM though, eventually
resulting in a pointer dereference error when we access the higher half
of the context memory since it hasn't been mapped.

Fixes: 45643633 ("ARM: dts: bcm2711: Enable the display pipeline")
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>