eng builds: turn on cflags crapped on by 1efb2d59616237ea1e192a2beef917bd4332edb5

Change-Id: I58304b60157566ef7cc2cf81bb0a37f5dfe012aa
Added hgrep for only headers, and kgrep for Kconfig an defconfig files in kernel.

Change-Id: If69a30f668c33df9cd58bb0d7cfd619dfb12a316