support binderized drmfb-composer with HWC=drmfb option (v2)

support binderized drmfb-composer with HWC=drmfb option (v2)

android.hardware.graphics.composer@2.1-service.drmfb added to PRODUCT_PACKAGES

New logic is added in init_hal_hwcomposer() function to enable drmfb-composer
if HWC=drmfb cmdline option used vendor.hwcomposer-2-1.drmfb service is started

(v2) Remove android.hardware.graphics.composer@2.1-service in PRODUCT_PACKAGES
     as it was causing issues to drm_gralloc
     Remove 'stop vendor.hwcomposer-2-1' in init_hal_hwcomposer()

Many thanks to lambdadroid for drmfb-composer

Signed-off-by: Mauro Rossi <issor.oruam@gmail.com>