Suppress warnings from TensorFlow library

With the warning flags used in the Linux driver stack, a lot of warnings
are being produced when compiling the TensorFlow library. As this is a
thirdparty library not under our control, the warnings from the library
have been suppressed.

Change-Id: Ib12b0d3b15df36d5134e5404c13db875031703d3
Signed-off-by: Mikael Olsson <mikael.olsson@arm.com>