open-plc-utils: update to commit 6a07d621583cb86ddf2fddcacb41cc4cf28bf33a

This fixes an alignment issue on some platforms, which renders
some tools, e.g. plcID, unusable.

While at, switch to xz compression for the tarball, drop an already
mainlined patch and remove a meanswhile absolete compiler switch.

Signed-off-by: Michael Heimpold <mhei@heimpold.de>

utils/open-plc-utils/patches/100-musl-compat.patch

@@ -1,33 +0,0 @@
---- a/ether/readpacket.c
-+++ b/ether/readpacket.c
-@@ -70,6 +70,10 @@
- #include <memory.h>
- #include <errno.h>
- 
-+#if defined (__linux__)
-+#include <poll.h>
-+#endif
-+
- #include "../ether/channel.h"
- #include "../tools/memory.h"
- #include "../tools/error.h"
-@@ -95,8 +99,6 @@ ssize_t readpacket (struct channel const
- 
- #elif defined (__linux__)
- 
--#include <sys/poll.h>
--
- 	struct pollfd pollfd =
- 	{
- 		channel->fd,
---- a/serial/serial.c
-+++ b/serial/serial.c
-@@ -69,6 +69,8 @@
- 
- #if defined (WIN32)
- #include <Windows.h>
-+#else
-+#include <sys/select.h>
- #endif
- 
- /*====================================================================*