arm: Factor out FIT image node decompression

This patch factors out the FIT image node decompression currently
implemented in the arm64 boot code into a separate function in the FIT
code, so that it can be reused for other image nodes later.

BRANCH=None
BUG=None
TEST=Booted Kevin

Change-Id: I2297e377492692bce1eecec37aa4356c645cddfb
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1553457
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
3 files changed