scripts/kconfig.pl: allow regex syntax in filtering out config entries

This will be used to filter out some autogenerated config values from
the kernel config files

Signed-off-by: Felix Fietkau <nbd@nbd.name>

scripts/kconfig.pl

@@ -102,8 +102,15 @@ sub config_sub($$) {
 	my $cfg1 = shift;
 	my $cfg2 = shift;
 	my %config = %{$cfg1};
-	
-	foreach my $config (keys %$cfg2) {
+	my @keys = map {
+		my $expr = $_;
+		$expr =~ /[?.*]/ ?
+			map {
+				/^$expr$/ ? $_ : ()
+			} keys %config : $expr;
+	} keys %$cfg2;
+
+	foreach my $config (@keys) {
 		delete $config{$config};
 	}
 	return \%config;