arm64: dts: Reduce size of virtio block device for foundation model

Will Deacon observed that kvmtool uses a size of 0x200 for virtio
block memory region and that the virtio block spec only uses 31 bytes in
the device specific region at 0x100 so reduce the region to a less
wasteful 0x200.
Signed-off-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

arch/arm64/boot/dts/foundation-v8.dts

@@ -224,7 +224,7 @@ v2m_serial3: uart@0c0000 {
 
 			virtio_block@0130000 {
 				compatible = "virtio,mmio";
-				reg = <0x130000 0x1000>;
+				reg = <0x130000 0x200>;
 				interrupts = <42>;
 			};
 		};