This patch separates the PMU driver code from the low level
CCI driver code and enables the PMU driver for ARM64.

Introduces config options for both.

 ARM_CCI400_PORT_CTRL	- controls the low level driver code for
			  CCI400 ports.
 ARM_CCI400_PMU		- controls the PMU driver code
 ARM_CCI400_COMMON	- Common defintions for CCI400

This patch also changes:
 ARM_CCI - common code for probing the CCI devices. This can be
   used for adding support for newer CCI versions(e.g, CCI-500).

Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Kukjin Kim <kgene@kernel.org>
Cc: Abhilash Kesavan <a.kesavan@samsung.com>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Punit Agrawal <punit.agrawal@arm.com>
Acked-by: NSudeep Holla <sudeep.holla@arm.com>
Acked-by: NNicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: NPunit Agrawal <punit.agrawal@arm.com>
Signed-off-by: NSuzuki K. Poulose <suzuki.poulose@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>