[POWERPC] iSeries: allow CONFIG_CMDLINE

It doesn't hurt to have this enabled on legacy iSeries and will mean it
is available for a combined build.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/Kconfig

@@ -852,7 +852,6 @@ source "arch/powerpc/platforms/prep/Kconfig"
 
 config CMDLINE_BOOL
 	bool "Default bootloader kernel arguments"
-	depends on !PPC_ISERIES
 
 config CMDLINE
 	string "Initial kernel command string"