BoardConfig: Remove old unused/depreciated flags

Change-Id: I26c4e2149bb5391d2da6920288474419ffefc9b7
BoardConfig: cleanup

Change-Id: I3cae90bcfd8af7c9f906d11b158e0fbe1ecc5838
BoardConfig: tis flag is depreciated now since the drop of libhardware fork

Change-Id: I6435859c53aa200cbeac659acd6004125d84dd0f
BoardConfig: Bring back "TARGET_USES_OVERLAY" flag that got lost in merge

Change-Id: I8506268cc8956779c2febe0ddea0b46b20e5ed2f