ramdisk: unset custom read_ahead_kb for the internal flash

Change-Id: I0643ddf386433de23cb4a94ff734da6e058a3bbf
Lets test LEGACY_FB option since we're still using a bit old EGL

Change-Id: Ia06f9b554c1e842457c6d7afb7b3cbb8fd08f8fc

Conflicts:
	BoardConfig.mk
ramdisk: a quick workaround for akmd not running

Change-Id: I633416b1c9372410329407c4728324731a3974a6