select.2: Remove some ancient information about pre-POSIX types for 'timeout'

The discussion about pre-POSIX types for 'timeval' and 'timespec'
is rather old, and these days serves mainly to complicate the
page. Remove it.

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

man2/select.2

@@ -267,32 +267,34 @@ with the desired
 .IR sigmask ,
 avoiding the race.)
 .SS The timeout
-The time structures involved are defined in
-.I <sys/time.h>
-and look like
+The
+.I timeout
+argument for
+.BR select ()
+is a structure of the following type:
 .PP
 .in +4n
 .EX
 struct timeval {
-    long    tv_sec;         /* seconds */
-    long    tv_usec;        /* microseconds */
+    time_t      tv_sec;         /* seconds */
+    suseconds_t tv_usec;        /* microseconds */
 };
 .EE
 .in
 .PP
-and
+The corresponding argument for
+.BR pselect ()
+has the following type:
 .PP
 .in +4n
 .EX
 struct timespec {
-    long    tv_sec;         /* seconds */
-    long    tv_nsec;        /* nanoseconds */
+    time_t      tv_sec;         /* seconds */
+    long        tv_nsec;        /* nanoseconds */
 };
 .EE
 .in
 .PP
-(However, see below on the POSIX.1 versions.)
-.PP
 Some code calls
 .BR select ()
 with all three sets empty,
@@ -444,33 +446,6 @@ in the main program.
 or reading from a pipe that may be empty,
 nonblocking I/O is used when reading from and writing to the pipe.)
 .PP
-Concerning the types involved, the classical situation is that
-the two fields of a
-.I timeval
-structure are typed as
-.I long
-(as shown above), and the structure is defined in
-.IR <sys/time.h> .
-The POSIX.1 situation is
-.PP
-.in +4n
-.EX
-struct timeval {
-    time_t         tv_sec;     /* seconds */
-    suseconds_t    tv_usec;    /* microseconds */
-};
-.EE
-.in
-.PP
-where the structure is defined in
-.I <sys/select.h>
-and the data types
-.I time_t
-and
-.I suseconds_t
-are defined in
-.IR <sys/types.h> .
-.PP
 Concerning prototypes, the classical situation is that one should
 include
 .I <time.h>