clk: renesas: cpg-mssr: Document suitability for RZ/G1

The Renesas CPG/MSSR driver is already in active use for RZ/G1 since
commits c0b2d75d2a4bf6a3 ("clk: renesas: cpg-mssr: Add R8A7743 support")
and 9127d54bb8947159 ("clk: renesas: cpg-mssr: Add R8A7745 support").

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Stephen Boyd <sboyd@codeaurora.org>

drivers/clk/renesas/renesas-cpg-mssr.c

@@ -43,7 +43,7 @@
  * Module Standby and Software Reset register offets.
  *
  * If the registers exist, these are valid for SH-Mobile, R-Mobile,
- * R-Car Gen 2, and R-Car Gen 3.
+ * R-Car Gen2, R-Car Gen3, and RZ/G1.
  * These are NOT valid for R-Car Gen1 and RZ/A1!
  */