powerpc, 5xxx, 512x: remove support for mpc5xxx and mpc512x

There was for long time no activity in the mpx5xxx area.
We need to go further and convert to Kconfig, but it
turned out, nobody is interested anymore in mpc5xxx,
so remove it.

Signed-off-by: Heiko Schocher <hs@denx.de>
diff --git a/common/Kconfig b/common/Kconfig
index c49199b..27dde11 100644
--- a/common/Kconfig
+++ b/common/Kconfig
@@ -464,7 +464,7 @@
 
 config DISPLAY_CPUINFO
 	bool "Display information about the CPU during start up"
-	default y if ARM || NIOS2 || X86 || XTENSA || MPC5xxx
+	default y if ARM || NIOS2 || X86 || XTENSA
 	help
 	  Display information about the CPU that U-Boot is running on
 	  when U-Boot starts up. The function print_cpuinfo() is called