Set BUILDING_WITH_NINJA flag when parsing makefiles for ninja build

Distinguish between parsing makefiles in make for a pre-ninja build,
parsing makefiles in kati for a ninja build, and parsing makefiles in
make for a non-ninja build by leaving USE_NINJA=true enabled for the
kati pass but also setting BUILDING_WITH_NINJA.

Change-Id: I63f1ce1efe08cd86fdf41f8051901f720b38cfaf
2 files changed