Convert CONFIG_83XX_PCICLK to Kconfig

This converts the following to Kconfig:
   CONFIG_83XX_PCICLK

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/powerpc/cpu/mpc83xx/Kconfig b/arch/powerpc/cpu/mpc83xx/Kconfig
index d58d278..bcd8375 100644
--- a/arch/powerpc/cpu/mpc83xx/Kconfig
+++ b/arch/powerpc/cpu/mpc83xx/Kconfig
@@ -188,6 +188,13 @@
 source "arch/powerpc/cpu/mpc83xx/arbiter/Kconfig"
 source "arch/powerpc/cpu/mpc83xx/initreg/Kconfig"
 
+config 83XX_PCICLK
+	hex "PCI clock frequency"
+	default 0xDEADBEEF
+	help
+	  If required, the PCI clock frequency to use when configuring
+	  the host bridge.
+
 config FSL_ELBC
 	bool