fs: Convert CONFIG_CMD_CRAMFS to Kconfig

This converts the following to Kconfig:
   CONFIG_CMD_CRAMFS

Signed-off-by: Simon Glass <sjg@chromium.org>
[trini: imply CMD_CRAMFS for keymile]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/powerpc/cpu/mpc83xx/Kconfig b/arch/powerpc/cpu/mpc83xx/Kconfig
index bf3be50..4890e13 100644
--- a/arch/powerpc/cpu/mpc83xx/Kconfig
+++ b/arch/powerpc/cpu/mpc83xx/Kconfig
@@ -64,12 +64,15 @@
 
 config TARGET_KM8360
 	bool "Support km8360"
+	imply CMD_CRAMFS
 
 config TARGET_SUVD3
 	bool "Support suvd3"
+	imply CMD_CRAMFS
 
 config TARGET_TUXX1
 	bool "Support tuxx1"
+	imply CMD_CRAMFS
 
 config TARGET_TQM834X
 	bool "Support TQM834x"