drivers: soc: Add LLCC driver

LLCC (Last Level Cache Controller) provides additional cache memory
in the system. LLCC is partitioned into multiple slices and each
slice gets its own priority, size, ID and other config parameters.
LLCC driver programs these parameters for each slice. Clients that
are assigned to use LLCC need to get information such size & ID of the
slice they get and activate or deactivate the slice as needed. LLCC driver
provides API for the clients to perform these operations.

Change-Id: I49641a578ee004347a58a85cf350a5aa1f307ca9
Signed-off-by: Rishabh Bhatnagar <rishabhb@codeaurora.org>