arm64: dt marvell: Fix AP806 system controller size

arm64: dt marvell: Fix AP806 system controller size

Extend the container size to 0x2000 to include the gpio controller at
offset 0x1040.

While at it, add start address notation to the gpio node name to match
its 'offset' property.

Fixes: 3b212aedea35 ("arm64: dts: marvell: add gpio support for Armada
7K/8K")
Cc: <stable@vger.kernel.org>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>