build: -fno-tree-vectorize for -mfpu=neon

The best performance comes from deriving parallelization using mathematical proof of the original function, and autovectorizing compilers don't do this. Pretty much all they do is unroll loops.
Therefore: make sure -ftree-vectorize is turned off
source:
https://wiki.debian.org/ArmHardFloatPort/VfpComparison#NEON

Change-Id: I6729c97495e1f76fabcd28b9c37fa5bae70a92de

Conflicts:
	core/combo/TARGET_linux-arm.mk
	core/combo/arch/arm/armv7-a-neon.mk
Merge remote-tracking branch 'th/kitkat' into kitkat
Remove hardcoded toolchains

Change-Id: Ib2892208423b6b9798f729e8370e3dd2c7ee408c