mkconfig: also create CONFIG defines with BSD sed

Parsing of boards.cfg fails on FreeBSD with the error:

sed: 1: "/=/ {s/=/\t/;q } ; { s/ ...": extra characters at the end
of q command

BSD sed expects commands to be on seperate 'lines', hence it expects
an additional ; before the closing brackets.
BSD sed does not support \t, replaced by literal tab.

Signed-off-by: Jeroen Hofstee <jeroen@myspectrum.nl>
Cc: Marek Vasut <marek.vasut@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/mkconfig b/mkconfig
index 6ff533f..ecb6d4e 100755
--- a/mkconfig
+++ b/mkconfig
@@ -148,7 +148,7 @@
 echo "/* Automatically generated - do not edit */" >>config.h
 
 for i in ${TARGETS} ; do
-	i="`echo ${i} | sed '/=/ {s/=/\t/;q } ; { s/$/\t1/ }'`"
+	i="`echo ${i} | sed '/=/ {s/=/	/;q; } ; { s/$/	1/; }'`"
 	echo "#define CONFIG_${i}" >>config.h ;
 done