sparc64: Use linux generic time implementation

There is no need to sparc64 provide an arch-specific implementation to
route to POSIX one (which uses gettimeofday).  Linux one already handles
the case for architecture that does not have __NR_time.

No semantic changes, checked against a build for sparc64-linux-gnu.

	* sysdeps/unix/sysv/linux/sparc/sparc64/time.c: Remove file.