dt-bindings: host1x: Add Tegra186 information

Add the Tegra186-specific hypervisor-related register range
properties.
Signed-off-by: NMikko Perttunen <mperttunen@nvidia.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NThierry Reding <treding@nvidia.com>

Documentation/devicetree/bindings/display/tegra/nvidia,tegra20-host1x.txt

@@ -3,6 +3,10 @@ NVIDIA Tegra host1x
 Required properties:
 - compatible: "nvidia,tegra<chip>-host1x"
 - reg: Physical base address and length of the controller's registers.
+  For pre-Tegra186, one entry describing the whole register area.
+  For Tegra186, one entry for each entry in reg-names:
+    "vm" - VM region assigned to Linux
+    "hypervisor" - Hypervisor region (only if Linux acts as hypervisor)
 - interrupts: The interrupt outputs from the controller.
 - #address-cells: The number of cells used to represent physical base addresses
   in the host1x address space. Should be 1.