toolchain.inc: print XGCCPATH if it's set

To help a user debug issues, print the current XGCCPATH value if
it's set.

Change-Id: I69afdd1c93cfd4747547ecad0d5e1ab4c87511b7
Signed-off-by: Martin Roth <martinroth@google.com>
Reviewed-on: https://review.coreboot.org/12677
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

toolchain.inc

@@ -164,6 +164,10 @@ endif
 endif
 endif
 ifeq ($(COMPILERFAIL),1)
+ifneq ($(XGCCPATH),)
+$(warning )
+$(warning Path to your toolchain is currently set to '$(XGCCPATH)')
+endif
 $(warning )
 $(warning To build the entire coreboot toolchain: make crossgcc)
 ifeq ($(IASLFAIL),1)