OCL: Optimize OpenCL version of function reduce

Using local memory buffer instead global buffer for reduce matrix to column.

 check_regression=*OCL*Reduce*
 test_filter=*OCL*Reduce*
 test_modules=core
 build_examples=OFF 

http://ocl.itseez.com/intel/export/perf/pr/2918/report/

Change only
1. min/max operations 
2. sum/avg operations for horizontal reducing (flags = 1 in tests).