bnxt_en: Increase RING_IDLE minimum threshold to 50

This keeps the RING_IDLE flag set in hardware for higher coalesce
settings by default and improved latency.

Signed-off-by: Andy Gospodarek <gospo@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnxt/bnxt.c

@@ -7702,7 +7702,7 @@ static void bnxt_init_dflt_coal(struct bnxt *bp)
 	coal->coal_bufs = 30;
 	coal->coal_ticks_irq = 1;
 	coal->coal_bufs_irq = 2;
-	coal->idle_thresh = 25;
+	coal->idle_thresh = 50;
 	coal->bufs_per_record = 2;
 	coal->budget = 64;		/* NAPI budget */