dts: rp1: Set per-channel DMA burst limit

Give the DMAC property "snps,axi-max-burst-len" a value for each DMA
channel, encoding the fact that channels 1 and 2 are more capable
("heavy").

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

Author: pelwell

arch/arm64/boot/dts/broadcom/rp1.dtsi

@@ -1111,7 +1111,7 @@
 			snps,data-width = <4>; // (8 << 4) == 128 bits
 			snps,block-size = <0x40000 0x40000 0x40000 0x40000 0x40000 0x40000 0x40000 0x40000>;
 			snps,priority = <0 1 2 3 4 5 6 7>;
-			snps,axi-max-burst-len = <4>;
+			snps,axi-max-burst-len = <8 8 4 4 4 4 4 4>;
 			status = "disabled";
 		};