dt-bindings: phy: samsung,mipi-video-phy: document exynos7870 MIPI phy

The Exynos7870 MIPI PHY device contains one DSIM PHY block and three
CSIS PHY blocks. It also requires two sysregs, one for display, and the
other for cameras. Document this device.

Signed-off-by: Kaustabh Chakraborty <kauschluss@disroot.org>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20250612-exynos7870-mipi-phy-v1-1-3fff0b62d9d3@disroot.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Documentation/devicetree/bindings/phy/samsung,mipi-video-phy.yaml

@@ -29,6 +29,7 @@ properties:
       - samsung,s5pv210-mipi-video-phy
       - samsung,exynos5420-mipi-video-phy
       - samsung,exynos5433-mipi-video-phy
+      - samsung,exynos7870-mipi-video-phy
 
   "#phy-cells":
     const: 1
@@ -46,19 +47,20 @@ properties:
     deprecated: true
     description:
       Phandle to PMU system controller interface, valid for
-      samsung,exynos5433-mipi-video-phy (if not a child of PMU).
+      samsung,exynos5433-mipi-video-phy and samsung,exynos7870-mipi-video-phy
+      (if not a child of PMU).
 
   samsung,disp-sysreg:
     $ref: /schemas/types.yaml#/definitions/phandle
     description:
       Phandle to DISP system controller interface, valid for
-      samsung,exynos5433-mipi-video-phy.
+      samsung,exynos5433-mipi-video-phy and samsung,exynos7870-mipi-video-phy.
 
   samsung,cam0-sysreg:
     $ref: /schemas/types.yaml#/definitions/phandle
     description:
       Phandle to CAM0 system controller interface, valid for
-      samsung,exynos5433-mipi-video-phy.
+      samsung,exynos5433-mipi-video-phy and samsung,exynos7870-mipi-video-phy.
 
   samsung,cam1-sysreg:
     $ref: /schemas/types.yaml#/definitions/phandle
@@ -84,7 +86,13 @@ allOf:
         samsung,disp-sysreg: false
         samsung,cam0-sysreg: false
         samsung,cam1-sysreg: false
-    else:
+
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: samsung,exynos5433-mipi-video-phy
+    then:
       properties:
         syscon: false
       required:
@@ -92,6 +100,19 @@ allOf:
         - samsung,cam0-sysreg
         - samsung,cam1-sysreg
 
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: samsung,exynos7870-mipi-video-phy
+    then:
+      properties:
+        syscon: false
+        samsung,cam1-sysreg: false
+      required:
+        - samsung,disp-sysreg
+        - samsung,cam0-sysreg
+
 additionalProperties: false
 
 examples: