Add more POSIX compliance macros to fix uClibc support
- Add POSIX 1993.09 compliance macro in source files that use "struct timespec";
- Add POSIX 2001.12 compliance macro in source files that use "struct sigaction" and the SA_SIGINFO macro, or the fchmod() function;
- Add POSIX 2008.09 compliance macro in source files that use the getline() function.
These compliance macros are enough for wlroots to compile with the git-master version of uClibc-ng.
Signed-off-by: Paul Cercueil paul@crapouillou.net