fdm: fix musl compile

musl does not define some macros so define them ourselves

Signed-off-by: Dirk Neukirchen <dirkneukirchen@web.de>

mail/fdm/patches/010-musl_WAIT_ANY.patch

@@ -0,0 +1,13 @@
+--- a/fdm.c
++++ b/fdm.c
+@@ -22,6 +22,10 @@
+ #include <sys/utsname.h>
+ #include <sys/wait.h>
+ 
++#ifndef WAIT_ANY
++#define WAIT_ANY (-1)
++#endif
++
+ #include <errno.h>
+ #include <fcntl.h>
+ #include <fnmatch.h>