sh: clkfwk: Rework legacy CPG clock handling.

This moves out the old legacy CPG clocks to their own file, and converts
over the existing users. With these clocks going away and each CPU
dealing with them on their own, CPUs can gradually move over to the new
interface.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index fb75c2d..d7990cd 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -513,6 +513,9 @@
 	  This is necessary for determining the reference clock value on
 	  platforms lacking an RTC.
 
+config SH_CLK_CPG_LEGACY
+	def_bool y
+
 config SH_CLK_MD
 	int "CPU Mode Pin Setting"
 	depends on CPU_SH2