MIPS: lantiq: dma: increase descritor count

NAT Performance results on BT Home Hub 5A (kernel 5.10.89, mtu 1500):

	Down		Up
Before	539 Mbps	599 Mbps
After	545 Mbps	625 Mbps
Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

arch/mips/include/asm/mach-lantiq/xway/xway_dma.h

@@ -8,7 +8,7 @@
 #define LTQ_DMA_H__
 
 #define LTQ_DESC_SIZE		0x08	/* each descriptor is 64bit */
-#define LTQ_DESC_NUM		0x40	/* 64 descriptors / channel */
+#define LTQ_DESC_NUM		0xC0	/* 192 descriptors / channel */
 
 #define LTQ_DMA_OWN		BIT(31) /* owner bit */
 #define LTQ_DMA_C		BIT(30) /* complete bit */