SiFive L2 Cache Controller
--------------------------
The SiFive Level 2 Cache Controller is used to provide access to fast copies
of memory for masters in a Core Complex. The Level 2 Cache Controller also
acts as directory-based coherency manager.
All the properties in ePAPR/DeviceTree specification applies for this platform

Required Properties:
--------------------
- compatible: Should be "sifive,fu540-c000-ccache" and "cache"

- cache-block-size: Specifies the block size in bytes of the cache.
  Should be 64

- cache-level: Should be set to 2 for a level 2 cache

- cache-sets: Specifies the number of associativity sets of the cache.
  Should be 1024

- cache-size: Specifies the size in bytes of the cache. Should be 2097152

- cache-unified: Specifies the cache is a unified cache

- interrupts: Must contain 3 entries (DirError, DataError and DataFail signals)

- reg: Physical base address and size of L2 cache controller registers map

Optional Properties:
--------------------
- next-level-cache: phandle to the next level cache if present.

- memory-region: reference to the reserved-memory for the L2 Loosely Integrated
  Memory region. The reserved memory node should be defined as per the bindings
  in reserved-memory.txt


Example:

	cache-controller@2010000 {
		compatible = "sifive,fu540-c000-ccache", "cache";
		cache-block-size = <64>;
		cache-level = <2>;
		cache-sets = <1024>;
		cache-size = <2097152>;
		cache-unified;
		interrupt-parent = <&plic0>;
		interrupts = <1 2 3>;
		reg = <0x0 0x2010000 0x0 0x1000>;
		next-level-cache = <&L25 &L40 &L36>;
		memory-region = <&l2_lim>;
	};
