Use New 4.8 Host Toolchain from Google

* While we are fixing SM Host Toolchains let's use the latest Google.

Change-Id: I1d5103c624e8e5bb93f8a46038cfd57263c69b76
Signed-off-by: Chet Kener <Cl3Kener@gmail.com>
pathmap: Point QC HAL pathmaps directly to the source

Directly map to the actual HAL directory, including the
board platform. This lets project-path-for point directly
to the respective HALs.

Change-Id: Ic4ed61bbdea9d0b5683502bf84a8410e76858527
"LRX21U"
"LRX21V"
build: set qcom media variant to root path

Change-Id: If7d0dc3fc1789b14f5272be46c13a9146575ce79