ps: add times & cputimes format specifiers: cumulative CPU time in seconds

These format specifiers are to time & cputime what etimes is to etime.

Signed-off-by: Sébastien Bigaret <sebastien.bigaret@telecom-bretagne.eu>

ps/ps.1

@@ -1192,6 +1192,11 @@ cumulative CPU time, "[DD\-]hh:mm:ss" format.  (alias
 .BR time ).
 T}
 
+cputimes	TIME	T{
+cumulative CPU time in seconds (alias
+.BR times ).
+T}
+
 drs	DRS	T{
 data resident set size, the amount of physical memory devoted to other than
 executable code.
@@ -1727,6 +1732,11 @@ cumulative CPU\ time, "[DD\-]HH:MM:SS" format.  (alias
 .BR cputime ).
 T}
 
+times	TIME	T{
+cumulative CPU\ time in seconds (alias
+.BR cputimes ).
+T}
+
 tname	TTY	T{
 controlling tty (terminal).  (alias
 .BR tt , \ tty ).