remove srecswap.pl, never seen modern jtag requiring it

tools/srecswap.pl

@@ -1,35 +0,0 @@
-#!/usr/bin/perl
-
-# endian-swap S records; we need this because the JTAG tools we're using
-# expect the memory image in byte-swapped format
-#
-# Jonathan Westhues, April 2004
-
-if(@ARGV == 0) {
-    die "usage: $0 file-to-endian-swap.s19 > out.s19\n";
-}
-
-while(<>) {
-    chomp;
-
-    if(/^S0/) {
-        next;
-    }
-    if(/^S7/) {
-        print "$_\n";
-        next;
-    }
-
-    if(not /^S3(..)(........)(.*)(..)$/) {
-        die "bad S record at line $.\n";
-    }
-
-    $data = $3;
-    $checksum = $4;
-
-    print "S3$1$2";
-    while($data =~ m#(..)(..)(..)(..)#g) {
-        print "$4$3$2$1";
-    }
-    print "$checksum\n";
-}