pgsql: New versions of mingw have gettimeofday(), so add an autoconf

Log Message:
-----------
New versions of mingw have gettimeofday(), so add an autoconf test
for this.

Modified Files:
--------------
pgsql:
configure (r1.565 -> r1.566)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/configure?r1=1.565&r2=1.566)
configure.in (r1.531 -> r1.532)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/configure.in?r1=1.531&r2=1.532)
pgsql/src/include:
pg_config.h.in (r1.124 -> r1.125)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/pg_config.h.in?r1=1.124&r2=1.125)
port.h (r1.113 -> r1.114)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/port.h?r1=1.113&r2=1.114)
pgsql/src/include/port:
win32.h (r1.77 -> r1.78)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/port/win32.h?r1=1.77&r2=1.78)