Revert "display: Switch to the qcom/CAF variant"

This reverts commit ea381ad8405a44ef3868b2b593ce3e9010d97993.
remove unsupported overlays on pure aosp
lets use prebuilt kernel :)
add VM tweaks
thanks to ctfrommn
add prefetch optimization
mako: do not use global cpp flag

at least the result is the same but let us user the
propper way like we do it with all flags and do not
set if over a global cpp flag

Change-Id: I1b7a229226af96cdfd294752823939a2cf870649