soc: ti: add Keystone Navigator QMSS driver

The QMSS (Queue Manager Sub System) found on Keystone SOCs is one of
the main hardware sub system which forms the backbone of the Keystone
Multi-core Navigator. QMSS consist of queue managers, packed-data structure
processors(PDSP), linking RAM, descriptor pools and infrastructure
Packet DMA.

The Queue Manager is a hardware module that is responsible for accelerating
management of the packet queues. Packets are queued/de-queued by writing or
reading descriptor address to a particular memory mapped location. The PDSPs
perform QMSS related functions like accumulation, QoS, or event management.
Linking RAM registers are used to link the descriptors which are stored in
descriptor RAM. Descriptor RAM is configurable as internal or external memory.

The QMSS driver manages the PDSP setups, linking RAM regions,
queue pool management (allocation, push, pop and notify) and descriptor
pool management. The specifics on the device tree bindings for
QMSS can be found in:
	Documentation/devicetree/bindings/soc/keystone-navigator-qmss.txt

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Kumar Gala <galak@codeaurora.org>
Cc: Olof Johansson <olof@lixom.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Sandeep Nair <sandeep_n@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>