fix win32 gettimeofday for mingw

here are the problems that I found while compiling libwebsockets with
CMake using as a generator MinGW Makefiles.

1. In http://git.warmcat.com/cgi-bin/cgit/libwebsockets/plain/win32port/win32helpers/gettimeofday.c

Remove spaces around time.h, otherwise it looks for " time.h " and
fails with "No such file ..."

I also needed to comment out

struct timezone
{
  int  tz_minuteswest; /* minutes W of Greenwich */
  int  tz_dsttime;     /* type of dst correction */
};

It is already declared in mingw's time.h

Signed-off-by: Arokux B <arokux@gmail.com>
normalize formatting in gettimeofday

Signed-off-by: Andy Green <andy.green@linaro.org>
cmake mingw no need for websock w32

2.  Comment out this line

http://git.warmcat.com/cgi-bin/cgit/libwebsockets/tree/CMakeLists.txt#n279

the file websock-w32.c is already compiled indirectly from libwebsockets.c

Signed-off-by: Arokux B <arokux@gmail.com>