dt-bindings: PHY: P2U: Add support for Tegra234 P2U block

Add support for Tegra234 P2U (PIPE to UPHY) module block which is a glue
module instantiated once for each PCIe lane between Synopsys DesignWare
core based PCIe IP and Universal PHY block.
Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220629060435.25297-2-vidyas@nvidia.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Documentation/devicetree/bindings/phy/phy-tegra194-p2u.yaml

@@ -4,7 +4,7 @@
 $id: "http://devicetree.org/schemas/phy/phy-tegra194-p2u.yaml#"
 $schema: "http://devicetree.org/meta-schemas/core.yaml#"
 
-title: NVIDIA Tegra194 P2U binding
+title: NVIDIA Tegra194 & Tegra234 P2U binding
 
 maintainers:
   - Thierry Reding <treding@nvidia.com>
@@ -12,13 +12,17 @@ maintainers:
 description: >
   Tegra194 has two PHY bricks namely HSIO (High Speed IO) and NVHS (NVIDIA High
   Speed) each interfacing with 12 and 8 P2U instances respectively.
+  Tegra234 has three PHY bricks namely HSIO, NVHS and GBE (Gigabit Ethernet)
+  each interfacing with 8, 8 and 8 P2U instances respectively.
   A P2U instance is a glue logic between Synopsys DesignWare Core PCIe IP's PIPE
-  interface and PHY of HSIO/NVHS bricks. Each P2U instance represents one PCIe
-  lane.
+  interface and PHY of HSIO/NVHS/GBE bricks. Each P2U instance represents one
+  PCIe lane.
 
 properties:
   compatible:
-    const: nvidia,tegra194-p2u
+    enum:
+      - nvidia,tegra194-p2u
+      - nvidia,tegra234-p2u
 
   reg:
     maxItems: 1
@@ -28,6 +32,11 @@ properties:
     items:
       - const: ctl
 
+  nvidia,skip-sz-protect-en:
+    description: Should be present if two PCIe retimers are present between
+      the root port and its immediate downstream device.
+    type: boolean
+
   '#phy-cells':
     const: 0