texi2pod.pl: add no-op --no-split option support [PR28144]

Change 2faf902da ("generate single html manual page by default")
added use of --no-split option to makeinfo. binutils reuses
makeinfo options for texi2pod.pl wrapper. Unsupported option
led to silent manpage truncation.

The change adds no-op option support.

etc/

	* texi2pod.pl: Handle no-op --no-split option.

etc/texi2pod.pl

@@ -59,6 +59,8 @@ while ($_ = shift) {
 	    $flag = shift;
 	}
         push (@ipath, $flag);
+    } elsif (/^--no-split$/) {
+	# ignore option for makeinfo compatibility
     } elsif (/^-/) {
 	usage();
     } else {