Fix case where boot/recovery.img were being built with wrong params.

The boot and recovery images  now get built using the same params during ota package
generation as during a normal build.

Change-Id: I93d46e11a4245288f0e87c87a2e4bf45ac5aff69
Fix the extra dt.img compilation issue.

Add support for optional device tree image (dt.img)
for device that doesnt have TARGET_BOOTIMAGE_USE_EXT2

Change-Id: I6e07b3ca6d049a8ebdad7ea304b4f39e7c846151
build: Add support for vendor product and device name

 * CM's build system assumes some convention-over-configuration which
   we might need to override in order to conform to vendor requirements.
 * Allow overriding of target and product names using these new
   variables. This allows for CM conventions to work, while generating
   the correct fingerprint dynamically without post processing the
   strings.

Change-Id: Ic5913e587400dd38c04aa05de3a7becced77a59e

Conflicts:
	core/Makefile