cm: Update use of vendor/extra `

 * Use inherit-product to pick up extra configuration

Change-Id: Icb0c8b09cd10b503e2dca09b7a972a613c354e7d
Merge branch 'cm-11.0' of https://www.github.com/CyanogenMod/android_vendor_cm into HEAD

Conflicts:
	config/common.mk