ARM: dts: armada-xp: add buffer manager nodes

Armada XP network controller supports hardware buffer management (BM).
Since it is now enabled in mvneta driver, appropriate nodes can be added
to armada-xp.dtsi - for the actual common BM unit (bm@c0000) and its
internal SRAM (bm-bppi), which is used for indirect access to buffer
pointer ring residing in DRAM.

Pools - ports mapping, bm-bppi entry in 'soc' node's ranges and optional
parameters are supposed to be set in board files.

Signed-off-by: Marcin Wojtas <[e-mail]>
Signed-off-by: Gregory CLEMENT <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

arch/arm/boot/dts/armada-xp.dtsi

···
 				marvell,crypto-sram-size = <0x800>;
 			};
 
+			bm: bm@c0000 {
+				compatible = "marvell,armada-380-neta-bm";
+				reg = <0xc0000 0xac>;
+				clocks = <&gateclk 13>;
+				internal-mem = <&bm_bppi>;
+				status = "disabled";
+			};
+
 			xor@f0900 {
 				compatible = "marvell,orion-xor";
 				reg = <0xF0900 0x100
···
 			#address-cells = <1>;
 			#size-cells = <1>;
 			ranges = <0 MBUS_ID(0x09, 0x05) 0 0x800>;
+		};
+
+		bm_bppi: bm-bppi {
+			compatible = "mmio-sram";
+			reg = <MBUS_ID(0x0c, 0x04) 0 0x100000>;
+			ranges = <0 MBUS_ID(0x0c, 0x04) 0 0x100000>;
+			#address-cells = <1>;
+			#size-cells = <1>;
+			clocks = <&gateclk 13>;
+			no-memory-wc;
+			status = "disabled";
 		};
 	};