Revert "inline kernel dtb build"

This reverts commit 3d1166301ea925894e2d5606ce31df2f2b843cc5.
build: edify: fix multiple device assert

Only generate one error message since multiple error message
will trigger a fail if the device does not match the first
assert

Change-Id: I1dc47cce10032eb28bbb808482b5ee9efc3b87bc

Conflicts:
	tools/releasetools/edify_generator.py