Remove check for time.h and HAVE_TIME_H

The `<time.h>` header file is part of the standard C89 headers [1] and
on current systems can be included unconditionally.

Refs:
[1] https://port70.net/~nsz/c/c89/c89-draft.html#4.1.2
[2] https://git.savannah.gnu.org/cgit/autoconf.git/tree/lib/autoconf/headers.m4

Author: petk

Zend/zend_hrtime.h

@@ -24,9 +24,7 @@
 #ifdef HAVE_UNISTD_H
 # include <unistd.h>
 #endif
-#ifdef HAVE_TIME_H
-# include <time.h>
-#endif
+#include <time.h>
 
 /* This file reuses code parts from the cross-platform timer library
 	Public Domain - 2011 Mattias Jansson / Rampant Pixels */

configure.ac

@@ -396,7 +396,6 @@ dirent.h \
 sys/param.h \
 sys/types.h \
 sys/time.h \
-time.h \
 netinet/in.h \
 alloca.h \
 arpa/inet.h \