defconfig: make ROW IO scheduler default
Make my conservative settings for smartmax the default.

You can still override them in the usual ways, and you might want do
so if performance is more important to you than battery life.
Bump localversion to carcosa-a21
Implemented F2FS for use on /data

Based on commit 4776c688c705b46925f9c9e1e6daf09692519fcf of Google's
Tegra 3 kernel for the 2012 Nexus 7.

Patches thanks to Now Computing's f2fs-backports repo:
https://github.com/nowcomputing/f2fs-backports/
defconfig: enable f2fs driver
Makefile: bump local version to carcosa-a22