m68knommu: improve the clock configuration defaults

Create some intelligent default settings for each ColdFire SoC type
in the configuration entry for CONFIG_CLOCK_FREQ.

The ColdFire clock frequency is configurable at build time. There is a
lot of variation in the frequency of operation on specific ColdFire based
boards. But we can choose a default that matches the maximum frequency
of clock operation for a particular ColdFire part. That is typically
the most common clock setting.
Signed-off-by: NGreg Ungerer <gerg@uclinux.org>
Acked-by: NGeert Uytterhoeven <geert@linux-m68k.org>

arch/m68k/Kconfig.cpu

@@ -418,6 +418,14 @@ config HAVE_IPSBAR
 
 config CLOCK_FREQ
 	int "Set the core clock frequency"
+	default "25000000" if M5206
+	default "54000000" if M5206e
+	default "166666666" if M520x
+	default "140000000" if M5249
+	default "150000000" if M527x || M523x
+	default "90000000" if M5307
+	default "50000000" if M5407
+	default "266000000" if M54xx
 	default "66666666"
 	depends on COLDFIRE
 	help