endeavoru: Update kernel zRAM configuration

Add CGROUP_MEM support to the kernel, austensibly to support zRAM.
We already have SWAP and ZRAM enabled in the kernel, so these two
lines make us match the recommendation by Google at
http://source.android.com/devices/low-ram.html

(Note that we don't currently USE zRAM, since it's not in the UI
and not in the init/fstab/et al...)

Change-Id: I1534080632b9037775fddbfbbd4a6a2b865bf929