clk: renesas: r8a7796: Add CPEX clock

Implement support for the CPEX clock on R-Car M3-W.  This clock can be
selected as a clock source for CMT1 (Compare Match Timer Type 1).
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Stephen Boyd <sboyd@kernel.org>

drivers/clk/renesas/r8a7796-cpg-mssr.c

@@ -103,6 +103,7 @@ static const struct cpg_core_clk r8a7796_core_clks[] __initconst = {
 
 	DEF_FIXED("cl",         R8A7796_CLK_CL,    CLK_PLL1_DIV2, 48, 1),
 	DEF_FIXED("cp",         R8A7796_CLK_CP,    CLK_EXTAL,      2, 1),
+	DEF_FIXED("cpex",       R8A7796_CLK_CPEX,  CLK_EXTAL,      2, 1),
 
 	DEF_DIV6P1("canfd",     R8A7796_CLK_CANFD, CLK_PLL1_DIV4, 0x244),
 	DEF_DIV6P1("csi0",      R8A7796_CLK_CSI0,  CLK_PLL1_DIV4, 0x00c),