mdp: Disable early suspend only for the MDP driver

Early suspend is deprecated in the framework but disabling it
completely can affect other subsystems. Disabling only for the
MDP driver.
add Content Adaptive Backlight Control
add exFat, (support 64Gb SDCard)
mm: pass readahead info down to the i/o scheduler

Some i/o schedulers (i.e. row-iosched, cfq-iosched) deploy an idling
algorithm in order to be better synced with the readahead algorithm.
Idling is a prediction algorithm for incoming read requests.

In this patch we mark pages which are part of a readahead window, by
setting a newly introduced flag. With this flag, the i/o scheduler can
identify a request which is associated with a readahead page. This
enables the i/o scheduler's idling mechanism to be en-sync with the
readahead mechanism and, in turn, can increase read throughput.
tracing: add ftrace events for ion allocations

Add ftrace events for ion allocations to make it easier to profile
their performance.
little tune-up
update .defconfig