iflags: Eliminate perl smart match operator

As smart match operator reuiqres perl version 5.10.1 or later,
it is replaced with grep function.
This part of code is going to be completely removed once iflags
renovataion is done. This commit is a quick fix for a build error.

Signed-off-by: Jin Kyu Song <jin.kyu.song@intel.com>

insns.pl

@@ -483,7 +483,7 @@ sub format_insn($$$$$) {
     # check if two different insn set types are set
     $cnt = 0;
     foreach $fla (split(/,/, $flags)) {
-        if ($fla ~~ @iflags) {
+        if (grep(/$fla/, @iflags)) {
             $cnt++;
             if ($cnt >= 2) {
                 die "Too many insn set flags in $flags\n";