Squash of the below two commits
* msm8226-common: Generate graphics vendor Makefile if missing
This allows to build CM without cloning vendor repos.
Change-Id: I87777485edc5f29c5899091176e55d28e36bb263
* msm8226-common: Fix blobs extraction with no vendor repos
Commit bff1cb1def84 ("msm8226-common: Generate graphics vendor
Makefile if missing") fixed only the generation of the makefiles,
but it didn't take care of the actual extraction of the blobs.
Change-Id: Idd38fbff554c0dac4b7cb8a867abb017bf37afc3
Change-Id: I3d6b70c8fdedfb624791fe3281c02df1c190d598