xcompile: Add separation for architectures to improve readability

- Add bar at the top of each architecture
- Make the architecture name and the TARCH_SEARCH to two lines
- Add a second line at the bottom of each architecture
- Add a comment about the two blank lines so they don't get
accidentally removed.

Change-Id: Ib4326bd94fe39b979244816ce54b752d083f6b16
Signed-off-by: Martin Roth <martinroth@google.com>
Reviewed-on: https://review.coreboot.org/12838
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

util/xcompile/xcompile

@@ -225,7 +225,9 @@ STRIP_${TARCH}:=${GCCPREFIX}strip
 AR_${TARCH}:=${GCCPREFIX}ar
 CROSS_COMPILE_${TARCH}:=${GCCPREFIX}
 
+
 EOF
+#The two blank lines above are intentional separators
 }
 
 # Architecture definitions
@@ -320,7 +322,9 @@ test_architecture() {
 		search="$search $toolchain-linux-gnu-"
 		search="$search $toolchain-"
 	done
-	echo "# $architecture TARCH_SEARCH=$search"
+	echo "###########################################################################"
+	echo "# $architecture"
+	echo "# TARCH_SEARCH=$search"
 
 	# Search toolchain by checking assembler capability.
 	for TBFDARCH in $TBFDARCHS; do