clk: shmobile: Add r8a7778 SoC to MSTP bindings

Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

Documentation/devicetree/bindings/clock/renesas,cpg-mstp-clocks.txt

@@ -13,6 +13,7 @@ Required Properties:
     - "renesas,r7s72100-mstp-clocks" for R7S72100 (RZ) MSTP gate clocks
     - "renesas,r8a73a4-mstp-clocks" for R8A73A4 (R-Mobile APE6) MSTP gate clocks
     - "renesas,r8a7740-mstp-clocks" for R8A7740 (R-Mobile A1) MSTP gate clocks
+    - "renesas,r8a7778-mstp-clocks" for R8A7778 (R-Car M1) MSTP gate clocks
     - "renesas,r8a7779-mstp-clocks" for R8A7779 (R-Car H1) MSTP gate clocks
     - "renesas,r8a7790-mstp-clocks" for R8A7790 (R-Car H2) MSTP gate clocks
     - "renesas,r8a7791-mstp-clocks" for R8A7791 (R-Car M2) MSTP gate clocks