buildgcc: fix compilation of IASL

IASL was broken when compiling without GCC.

Change-Id: Ib859ce41c1dda10181781c025fc378504f5ebb91
Signed-off-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-on: http://review.coreboot.org/10495
Tested-by: build bot (Jenkins)
Reviewed-by: Edward O'Callaghan <edward.ocallaghan@koparo.com>

util/crossgcc/buildgcc

@@ -562,8 +562,8 @@ fi
 
 # Set up host compiler and flags needed for various OSes
 
-if [[ "$PACKAGES" == *GCC* ]]; then
 CC=cc
+if [[ "$PACKAGES" == *GCC* ]]; then
 if [ $UNAME = "Darwin" ]; then
 	#GCC_OPTIONS="$GCC_OPTIONS --enable-threads=posix"