dm: Change CMD_DM enabling

CMD_DM is used for debug purpose and it shouldn't be enabled by default
via Kconfig. Unfortunately this is in the tree for quite a long time
that's why solution is to use imply DM for all targets which are
enabling DM.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/arch/powerpc/cpu/mpc83xx/Kconfig b/arch/powerpc/cpu/mpc83xx/Kconfig
index 385a7a6..571cf8f 100644
--- a/arch/powerpc/cpu/mpc83xx/Kconfig
+++ b/arch/powerpc/cpu/mpc83xx/Kconfig
@@ -64,6 +64,7 @@
 config TARGET_IDS8313
 	bool "Support ids8313"
 	select DM
+	imply CMD_DM
 
 config TARGET_KM8360
 	bool "Support km8360"