Adding MKL op for reshape and several fixes to other ops (#9228)

* Bug fixes to max/avg pooling

* Added fixes for unexpected behaviour of OP_REQUIRES

* Fix to get common_runtime/function_test to pass with MKL. Removes eigen label from test function when compiled with mkl flag

* MKL Reshape

* MKL Reshape (by Amin)

* Bug fixes to max/avg pooling

* Added fixes for unexpected behaviour of OP_REQUIRES

* Fix to get common_runtime/function_test to pass with MKL. Removes eigen label from test function when compiled with mkl flag

* MKL Reshape (by Amin)

* Fixed duplication caused during merge

* Modified Mkl Layer and Op Registry

* config for mkl

* Addressed PR comments

* Mkl ops ordered alphabetically in tensorflow/core/BUILD