Even though both CCI-400 and CCI-500 IPs have different configurations
with respect to the number and types of supported interfaces, their
register offsets and programming sequences are similar. This patch
creates a common driver for enabling and disabling snoop transactions
and DVMs with both the IPs.

New platform ports which implement one of these IPs should use this
common driver. Existing platform ports which implement CCI-400 should
migrate to the common driver as the standalone CCI-400 will be
deprecated in the future.

Change-Id: I3ccd0eb7b062922d2e4a374ff8c21e79fa357556