package/ola: fix build with musl 1.2.3

Fix the following build failure with musl 1.2.3:

ola/AutoStart.cpp: In function 'ola::network::TCPSocket* ola::client::ConnectToServer(short unsigned int)':
ola/AutoStart.cpp:116:12: error: invalid cast from type 'std::nullptr_t' to type 'char*'
  116 |            reinterpret_cast<char*>(NULL));
      |            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Fixes:
 - http://autobuild.buildroot.org/results/88be323e64f66433cabc962e719307b5fb6a6177

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
(cherry picked from commit e23b230a20)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/ola/0001-ola-fix-compilation-with-musl-1-2-3.patch

@@ -0,0 +1,35 @@
+From eb31017284f9a1c95602a9c06d606df6b558a691 Mon Sep 17 00:00:00 2001
+From: Rosen Penev <rosenp@gmail.com>
+Date: Thu, 14 Apr 2022 17:39:32 -0700
+Subject: [PATCH] ola: fix compilation with musl 1.2.3
+
+musl 1.2.3 defines NULL as nullptr. cannot use reinterpret_cast with
+nullptr.
+
+Signed-off-by: Rosen Penev <rosenp@gmail.com>
+[Retrieved from:
+https://github.com/OpenLightingProject/ola/pull/1773/commits/eb31017284f9a1c95602a9c06d606df6b558a691]
+Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
+---
+ ola/AutoStart.cpp | 6 +++---
+ 1 file changed, 3 insertions(+), 3 deletions(-)
+
+diff --git a/ola/AutoStart.cpp b/ola/AutoStart.cpp
+index 89fa51f115..4dbe20d317 100644
+--- a/ola/AutoStart.cpp
++++ b/ola/AutoStart.cpp
+@@ -110,11 +110,11 @@ TCPSocket *ConnectToServer(unsigned short port) {
+     // Try to start the server, we pass --daemon (fork into background) and
+     // --syslog (log to syslog).
+     execlp("olad", "olad", "--daemon", "--syslog",
+-#ifdef __FreeBSD__
+-           reinterpret_cast<char*>(0));
++#if __cplusplus >= 201103L
++           nullptr);
+ #else
+            reinterpret_cast<char*>(NULL));
+-#endif  // __FreeBSD__
++#endif  // __cplusplus >= 201103L
+     OLA_WARN << "Failed to exec: " << strerror(errno);
+     _exit(1);
+   }