clk: renesas: Stop enabling legacy DT clock support by default

Since v4.15-rc1, the DTS files for all R-Car Gen2 SoCs have been
converted to the new CPG/MSSR bindings.  Hence it is now safe to no
longer enable legacy DT clock support by default.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

drivers/clk/renesas/Kconfig

@@ -24,12 +24,13 @@ if CLK_RENESAS
 config CLK_RENESAS_LEGACY
 	bool "Legacy DT clock support"
 	depends on CLK_R8A7790 || CLK_R8A7791 || CLK_R8A7792 || CLK_R8A7794
-	default y
 	help
 	  Enable backward compatibility with old device trees describing a
 	  hierarchical representation of the various CPG and MSTP clocks.
 
 	  Say Y if you want your kernel to work with old DTBs.
+	  It is safe to say N if you use the DTS that is supplied with the
+	  current kernel source tree.
 
 # SoC
 config CLK_EMEV2