nvethernet: define default PTP RxQ

Issue: PTP packets are received on RxQ0, with legacy
       perf data, which cause PTP getting delayed.

Fix:   If DT entry not present, use ETHER_DEFAULT_PTP_QUEUE

Bug 200766950

Change-Id: I25054caf23ffec37fcb422a7aa705b122da96394
Signed-off-by: Rakesh Goyal <rgoyal@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nvidia/+/2588641
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>
Reviewed-by: Bitan Biswas <bbiswas@nvidia.com>
Reviewed-by: svcacv <svcacv@nvidia.com>
Reviewed-by: Bhadram Varka <vbhadram@nvidia.com>
Reviewed-by: svc_kernel_abi <svc_kernel_abi@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
GVS: Gerrit_Virtual_Submit

drivers/net/ethernet/nvidia/nvethernet/ether_linux.h

@@ -107,6 +107,11 @@
  */
 #define ETHER_DFLT_PTP_CLK		312500000U
 
+/**
+ * @brief Ethernet default PTP default RxQ
+ */
+#define ETHER_DEFAULT_PTP_QUEUE		3U
+
 /**
  * @brief Ethernet clk rates
  */