drivers: llcc: Write to sub-cache register based on version

Check the llcc version before writing to write subcache register as
its not supported by older targets.

Change-Id: Ifc3f2d4d66612d6dcc6070d3cbc3fce97202ccf3
Signed-off-by: Rishabh Bhatnagar <rishabhb@codeaurora.org>