Make handling of cpp line information more tolerant

At least some cpp implementations, in at least some circumstances place
multiple numbers after the file name when they put line number information
into the output.  We don't really care what the content of these is, but
we want the dtc lexer not to choke on this, so adjust the rule for handling
cpp line number information accordingly.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

dtc-lexer.l

@@ -57,7 +57,7 @@ static void PRINTF(1, 2) lexical_error(const char *fmt, ...);
 			push_input_file(name);
 		}
 
-<*>^"#"(line)?[ \t]+[0-9]+[ \t]+{STRING}([ \t]+[0-9]+)? {
+<*>^"#"(line)?[ \t]+[0-9]+[ \t]+{STRING}([ \t]+[0-9]+)* {
 			char *line, *fnstart, *fnend;
 			struct data fn;
 			/* skip text before line # */