toolchain.inc: Skip how to use any toolchain if it's selected

If ANY_TOOLCHAIN is selected, don't bother telling the user how to
do what they've already done.

Change-Id: I7182d18a91e832aa56638ec64fe8b3b0c38cff7a
Signed-off-by: Martin Roth <martinroth@google.com>
Reviewed-on: https://review.coreboot.org/12679
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
diff --git a/toolchain.inc b/toolchain.inc
index ef3ae16..7a0864e 100644
--- a/toolchain.inc
+++ b/toolchain.inc
@@ -174,9 +174,13 @@
 endif #($(IASLFAIL),1)
 $(warning For more toolchain build targets: make help_toolchain)
 $(warning )
-$(warning *** To try to use your own toolchain, run 'make menuconfig', then select the)
-$(warning *** config option: General setup -> Allow building with any toolchain)
-$(error Note that this is NOT supported.  Using it means you're on your own)
+ifneq ($(CONFIG_ANY_TOOLCHAIN),y)
+$(warning To try to use any toolchain in your path, run 'make menuconfig', then select)
+$(warning the config option: 'General setup', and 'Allow building with any toolchain')
+$(warning Note that this is NOT supported.  Using it means you're on your own.)
+$(warning )
+endif #($(CONFIG_ANY_TOOLCHAIN),y)
+$(error Halting the build)
 endif #($(COMPILERFAIL),1)
 
 endif #($(NOCOMPILE),1)