MIPS: BCM63XX: fix ENETDMA_6345_MAXBURST_REG offset

The channels are only 0x40 bytes large, so 0x40 would be the next one's
CHANCFG_REG. Also the position makes it clear that this was intended to
be 0x04. So clearly a typo.
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: bcm-kernel-feedback-list@broadcom.com
Patchwork: https://patchwork.linux-mips.org/patch/15316/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/mach-bcm63xx/bcm63xx_regs.h

@@ -710,7 +710,7 @@
 /* Broadcom 6345 ENET DMA definitions */
 #define ENETDMA_6345_CHANCFG_REG	(0x00)
 
-#define ENETDMA_6345_MAXBURST_REG	(0x40)
+#define ENETDMA_6345_MAXBURST_REG	(0x04)
 
 #define ENETDMA_6345_RSTART_REG		(0x08)